Jeep over heat at midnight!

[Mudderoy]

Well I just took the wife down to Wendy's to get her a Frosty. It is about 2 miles down the road. I noticed after we left Wendy's the temp gauge was dead on the mark right after the 210 hash mark.

I watched it, and thought it was very strange. About 1/2 home the CHECK GAUGES light came on and the temp gauge had instantly gone from the hash mark I mention to the next to last hash mark. You know they one that gives you HOPE that you can make it?

Anyway windows down, heater on full, and it dropped back down to the first hash past the 210. I got home, got the flashlight, looked around.

I couldn't find anything. I turned the engine off waited, watched and listened.

Nothing. The overflow bottle was pretty full. No drips, no noises except the popping noise of hot engine bay. I did get the IR therometer out and checked the thermostat housing, 238.

After a few minutes of not finding any good reason why it would over heat, I fired it back up again. The A/C fan came on immediantly like it should with a high temp (A/C was off). I let it run, watching for leaks. After about 2 minutes, if that, the temp gauge started dropping.

I jumped in and watched the gauge. The A/C fan went off and now the temp was just above the 210 (about a needle's width). I thought maybe it was the A/C that caused it to over heat. So I turned on the A/C. The fan came back on and the temp gauge went lower, just a hair below the 210.

Okay now I am dumbfounded. What the hell!?!?!?! After watching it for about 10 minutes and seeing the gauge rock steady at just under 210 I took it for a drive.

I tried to stop, and accelerate like I did when we went to Wendy's. I drove around for a good 20 minutes, nothing, didn't move although it rose slightly to the 210 mark.

I don't know. I tried stopping the clutched fan with a papper towel tube and it just ate it up. Everything looks normal. I haven't checked the coolant level in the radiator yet, but I'll do that in the morning.

I'm thinking either the A/C fan wasn't on before, or the thermostat was stuck. I have to drive 100 miles tomorrow, so I was thinking about changing out the thermostat in the morning.

What else should I check, or consider?

Oh the coolant in the overflow was a nice bright green. The oil on the stick looked like oil. It just seems like something stopped working and then started working after I turned off the engine, waited 5 minutes, and turned it back on.

I did check the A/C fan connection, but it seemed fine. I cannot say for sure that the A/C fan was on before I pulled up in the driveway.

[XJcoupe]

well at the point that you over heated it, usually the thermostat sticks closed, and now its pooched, change that up 1st thing, but could be a underlining problem that caused it, like a bad, or warn water pump. how many miles on the OD ? you mentioned other things, but your probably thinking head gasket- ooch, I would think waterpump 1st, and change the therm. hope his helps ya- have a nice trip. cheers rob

[muddeprived]

The solution to your problem is in the first sentence. You didn't give your jeep a frosty so it overheated.

[Mudderoy]

well at the point that you over heated it, usually the thermostat sticks closed, and now its pooched, change that up 1st thing, but could be a underlining problem that caused it, like a bad, or warn water pump. how many miles on the OD ? you mentioned other things, but your probably thinking head gasket- ooch, I would think waterpump 1st, and change the therm. hope his helps ya- have a nice trip. cheers rob

150k I'm on my 5th water pump. The bearning when out in the last one. I guess it's been a couple of years now with this one.

I don't think it's a head gasket problem, especially after I restart the engine and temps go to normal, but I wanted to include the information for those that might think it is a head gasket. You never know.

It was really weird, like something wasn't working and then started working. I can see that happening with an electric fan, or a thermostat.

Dunno, but thanks for the information.

[BlueXJ]

Any updates?? Sounds like a fan that failed to cycle on to me. Wonder if the motor has a dead spot?

Note: Check the fan clutch when the motor is off and cold. Should just be able to turn it 90* or less and then with the motor off after operating temp has been reached at that stage you should not be able to move it more that an 1/8 of a turn.

[Mudderoy]

Any updates?? Sounds like a fan that failed to cycle on to me. Wonder if the motor has a dead spot?

Note: Check the fan clutch when the motor is off and cold. Should just be able to turn it 90* or less and then with the motor off after operating temp has been reached at that stage you should not be able to move it more that an 1/8 of a turn.

Yeah the more I think about it I'm thinking electric fan. I'll check the mechanical here in a few minutes. Was up late last night, just got up.

[Mudderoy]

Ok so I drove to Baytown today to pickup some CISCO equipment. 2 routers and a switch for $50!!! Anyway I drove 65 mph 2500 rpm and the temp rose to just about the middle of the 210 and the next hash mark. If I drove 70 to 75 the temp would get a little closer to the next hash mark.

After we got to Baytown I was driving 45 to 50 mph and them got closer to the 210. Outside temps are around 100 degrees here today, at least that what a Bank sign was saying, it's hot.

On the way back the Jeep smelled hot, but the temp was the same, and it ran fine. We got to my mother in-laws house and you could really smell the HOT smell, but IR scan on the thermostat housing said 207.

I think I'm going to see if I can get a exhaust gas test from the local autoparts. If it is a head leak it must really be a small one.

It may be time to get a high flow water pump if the gas test comes back good.

[firehawk]

A couple of things.

1. I have been told thermostats are made to fail in the OPEN position to make sure there is always coolant circulating.

2. If your electric fan didn't come on while using the A/C and the Jeep got THAT hot the compressor would have locked up. The head pressure would have gotten too high. I had that problem on a Tempo years ago sitting at the bank. The A/C ran fine until I heard the belt start to squall from the compressor locking up momentarely as the pressure got too high. There wasn't enough air moving past the condenser to pull the heat out of the system.

I will agree with the post about a dead spot in the motor for the electric fan. The cooling fan in my computer does that. I can get it to run simply by flicking the blade with something, and it will run fine until the computer get's shut off.

[Mudderoy]

Maybe that is why it started working after I turned off the engine for 5 minutes and restarted it.

I wonder it the electric fan could be causing all the issues.

I noticed it was running hotter on the way home from my mother in-laws. The only thing I changed was I was running the fan at the 3rd position, instead of the 2nd.

I dropped it to the 2nd speed and the temp dropped a little.

I remember last summer I could control the coolant temp by running the A/C or not. I think the condensor is generating a lot of heat, and transfering it to the radiator.

No leaks, not overflow in the overflow bottle, radiator is full, nothing seems to be wrong accept it is getting too hot at rpms above 2200.

Boy I really thought the 3 core was going to take care of this...

[Mudderoy]

I decided to pull the plugs today and see what they looked like.

http://xjtalk.com/images/special/jeepsparkplugs.jpg

I broke one so I went and bought a new set. Champion, along with a new rotor and cap.

I let the engine get warm and I never saw the coolant level drop, move etc, so I changed out the thermostat.

http://xjtalk.com/images/special/jeepcoolant.jpg

I took it for a test drive and it was more than a needles width beyond the 210 mark.

I dunno! I think I'm dealing with two problems now.

[BlueXJ]

Are you still thinking the fan is one of those two problems? What is the other?

[Mudderoy]

Are you still thinking the fan is one of those two problems? What is the other?

Well the problem (overheat at low speed) has not repeated itself.

A low speed over heat would be low coolant, fan(s), thermostat stuck closed, blown head gasket, bad water pump.

Since I turned off the engine and restarted it 5 minutes later, and temp went back to normal, I am thinking something wasn't on, fan for example. Or thermostat was unstuck for example.

When I was on the highway at 65 mph and the temp was running well over 210, that must be my second engine cooling problem.

If the fans don't make a diff at highway speeds, then I must have a bad water pump, a blown head gasket, a thermostat that is stuck part open, a collapsing lower hose, basically something that is impeding the flow of coolant from through the engine and radiator.

Someone mentioned that since I have 4.56 gears and 32" tires, I am revving higher, which means more engine heat. I am pushing more weight which means more heat. I added a 3 core radiator, but that additional cooled volume of coolant isn't enough, apparently.

I either have a blown head gasket, which looking at the spark plugs I don't see that. Or some major piece of the cooling system isn't doing the job.

I cannot rule out the collapsed hose, but it's a new hose and it even put in the spring from the old OEM hose.

I am thinking it must be the water pump. I cannot help but think a stock water pump with a 3 core radiator should be enough to cool this beast, so either the water pump was bad from the beginning or it went bad shortly after I installed it.

I only have problems (now) with the engine running hot during the HOT summer months.

[Mudderoy]

Any updates?? Sounds like a fan that failed to cycle on to me. Wonder if the motor has a dead spot?

Note: Check the fan clutch when the motor is off and cold. Should just be able to turn it 90* or less and then with the motor off after operating temp has been reached at that stage you should not be able to move it more that an 1/8 of a turn.

I checked it with the engine cold (as in overnight off) and it moved maybe 45 degrees, if that. I'll have to check it again with the engine hot, as I don't recall how much it moved, but it seemed like it move more than when it was cold.

[BlueXJ]

Sounds like the fan clutch may not be your problem Muddy.

[Mudderoy]

Sounds like the fan clutch may not be your problem Muddy.

The next time it overheats I'll make sure I check to see that the electric fan is running, if not then I know that is the problem.

It makes sense. We had the A/C on and it was pretty warm even at midnight. It took maybe 15 minutes, to over heat, and that included sitting in the drive through at Wendy's.

I only noticed it on the way back, right after we left Wendy's. I know from past experience that if I am not running the A/C and I am sitting in the drive through I'll hear the electric fan come on. When I first bought the Jeep I didn't know why it was making so much extra noise, but I did notice that the temp was above the normal 210. The temp would drop and the noise would stop. Shortly after that I looked and I saw the two fans.

So I bet the electric fan is going out, or the connection was loose. That was one of the things I checked after I got home and turned off the engine.

[muddeprived]

When you say overheat, do you mean it's at the redline? Mine goes up a couple notches when it's 90 around here. I kinda expect it cuz of the crammed up engine bay and lack of air under there, even with my vents. I don't worry much about it as long as it doesn't go near the redline. My 2000 dodge dakota did the same thing when it was really hot out. I guess it's normal? I don't expect the motor to stay at 210 ALL the time so I allow it to get hot and sweat, like we do :)

Do you run aftermarket electric fans? Maybe that would be a good investment. I'm not sure about xj's, but on our 4 cyl tj's we would remove the motor fan and install a dual electric fan setup that we could run by a switch. We gain a few HP from this mod cuz the engine no longer has to power it's own fan. My friend with a YJ did this mod on his and he kept the fan on when he drove it. The temp never went over 200 until he shut off the fan. I think the electric fans are a good investment. His blew up when he forgot to turn it off when dunking in a puddle. The blades exploded all over the place. :smiley-laughing021:

[Mudderoy]

When you say overheat, do you mean it's at the redline? Mine goes up a couple notches when it's 90 around here. I kinda expect it cuz of the crammed up engine bay and lack of air under there, even with my vents. I don't worry much about it as long as it doesn't go near the redline. My 2000 dodge dakota did the same thing when it was really hot out. I guess it's normal? I don't expect the motor to stay at 210 ALL the time so I allow it to get hot and sweat, like we do :)

Do you run aftermarket electric fans? Maybe that would be a good investment. I'm not sure about xj's, but on our 4 cyl tj's we would remove the motor fan and install a dual electric fan setup that we could run by a switch. We gain a few HP from this mod cuz the engine no longer has to power it's own fan. My friend with a YJ did this mod on his and he kept the fan on when he drove it. The temp never went over 200 until he shut off the fan. I think the electric fans are a good investment. His blew up when he forgot to turn it off when dunking in a puddle. The blades exploded all over the place. :smiley-laughing021:

Well when the overheat occured Friday night around midnight, it was red line, the first red hash mark. It did that wonderful thing where it gets to the first hash mark after the 210 hash, sits there for a few minutes then instantly the needle jumps to the first redline hash mark.

Saturday when we drove the 50 miles to Baytown it ran hot, it did not overheat. Overheating was my fear since it was running close to that dreaded hash mark just after the 210. Experience has told me that once it gets there it is just a matter of time before it jumps to the redline.

My plan was to get an electric fan before THIS summer, but as someone told me if it is running hot on the freeway an electric fan isn't going to solve the problem.

That is why I think I had two problems. The overheat Friday night, and the running hot on the freeway I now believe are two issues, just both with the cooling system.

[Mudderoy]

Ok as I stated before I replaced the thermostat with a 180 from Oreilly's. I really didn't want to because what I had in there was a "HI-FLOW" thermostat, but screw it.

Well driving to work this morning it took 12 miles before the temp was over 190. At the 15 mile mark, I was sitting at a light and the temp went just over 210, maybe 1/2 a needle's width.

I started moving again and the temp dropped (within a couple of miles) to 210 and by the time I was at the office (22 miles total) I was running just a tad under 210 (less than a needles width).

Now that's with the temp in the 80's. If it can do this on the way home in the upper 90's I'll be happy.

I noticed when I was replacing the thermostat that there is a large opening in sort of a retangle shape next to the round hole that the thermostat fits.

I thought this was strange because that notch basically allows coolant to go around the thermostat, at least that is how it looked to me.

If this is the case the coolant is always circulating no mater if the thermostat is open or not. It may also explain why my engine would run hotter at highway speeds and not at slower speeds.

If the flow was restricted (water pump, blockage, thermostat stuck closed) then I would expect the heat to increase at higher rpm and load.

I dunno, I'll just be glad when we switch to electric motors and all you have to worry about is getting shocked and killed when you work on your Jeep.

[firehawk]

How old are those plugs? They look like you're running lean, as they are pretty white in color. The tips should be a slight tan/beige color. A lean condition can add to a overheating problem. Any problems with spark knock? I wonder if your dealing with a bad O2 sensor?

[Mudderoy]

How old are those plugs? They look like you're running lean, as they are pretty white in color. The tips should be a slight tan/beige color. A lean condition can add to a overheating problem. Any problems with spark knock? I wonder if your dealing with a bad O2 sensor?

At least a year old. I ran a OBDII data capture and according to what I was told from some folks at NAXJA I am running slightly rich.

Both O2 sensors have been replaced, in fact they were replaced before the 4.56 gears. Doesn't mean they are right, just replaced.

Wait I have that graph around here somewhere....

http://xjtalk.com/images/special/EngineO21_Test2.jpg

I do not have any knock, well nothing like I used to hear on 70's model cars. Maybe you are talking about something else? pre-detonation is what I think the technical name for it is.

[firehawk]

While I'm no expert, IMO there's no way you could be running rich with your plugs that white in color.

I've has to rejet a couple of motorcycles, and also my quad. If I saw a plug that color I would be bumping up a jet size ASAP! It's MUCH more critical in an aircooled engine.

[firehawk]

Your right, pre detonation is the correct term, I've always called it spark knock. What I'm refering to is a rattling/clattering sound.

[Mudderoy]

While I'm no expert, IMO there's no way you could be running rich with your plugs that white in color.

I've has to rejet a couple of motorcycles, and also my quad. If I saw a plug that color I would be bumping up a jet size ASAP! It's MUCH more critical in an aircooled engine.

Well that would certainly make since why the faster I go, or more load I put on the engine the hotter it would get.

Hmmm lean could be a glogged fuel filter, or clogged injectors. I guess the O2 sensors would be what told the ECM how much fuel was being burned?

[firehawk]

Well that would certainly make since why the faster I go, or more load I put on the engine the hotter it would get.

Hmmm lean could be a glogged fuel filter, or clogged injectors. I guess the O2 sensors would be what told the ECM how much fuel was being burned?

A bad O2 sensor could be telling the ECM your running rich when your not, and the ECM is leaning the fuel mixture out.

[Mudderoy]

A bad O2 sensor could be telling the ECM your running rich when your not, and the ECM is leaning the fuel mixture out.

Any idea where I can get a OEM O2 sensor that won't cost $150 to $300?

[BlueXJ]

Any idea where I can get a OEM O2 sensor that won't cost $150 to $300?

You would have a CEL and the codes would tell you the O2 sensor was faulty.

Muddy is your electric fan a curved blade or straight bladed version?

[firehawk]

Any idea where I can get a OEM O2 sensor that won't cost $150 to $300?

I think AutoZone sells Bosch O2 sensors for around $90. Not OEM though.:rolleyes:

[Mudderoy]

I think AutoZone sells Bosch O2 sensors for around $90. Not OEM though.:rolleyes:

Yep bought two bosch from Oreilly's and that's what I have in there now. :(

[Mudderoy]

You would have a CEL and the codes would tell you the O2 sensor was faulty.

Muddy is your electric fan a curved blade or straight bladed version?

http://xjtalk.com/images/special/jeepefan.jpg
Curvy "That's what SHE said!"

[BlueXJ]

http://xjtalk.com/images/special/jeepefan.jpg
Curvy "That's what SHE said!"

Guess that rules out my other theory.

[kryptonitexj]

Not trying to hijack. But yesterday after work I arrived at my apt. I hop out and all of a sudden I hear a huge gush of water pour out of my heep. I said Effin great!!!! now what. So I go inside to cool off a min and come back out pop the hood. Turns out the plastic tank on my "Heat buster" radiator grew a crack. A quick check with Orellie's I find out I bought the one with a Lifetime warranty. 20 min to pull it out and off to Orellie's to get a FREE replacement. 30 min to reinstall it, top it off with antifreeze and I'm back on the road. Thanks for letting me vent!!!! have a great day.

[Mudderoy]

Not trying to hijack. But yesterday after work I arrived at my apt. I hop out and all of a sudden I hear a huge gush of water pour out of my heep. I said Effin great!!!! now what. So I go inside to cool off a min and come back out pop the hood. Turns out the plastic tank on my "Heat buster" radiator grew a crack. A quick check with Orellie's I find out I bought the one with a Lifetime warranty. 20 min to pull it out and off to Orellie's to get a FREE replacement. 30 min to reinstall it, top it off with antifreeze and I'm back on the road. Thanks for letting me vent!!!! have a great day.

I hate plastic radiators! You are lucky you were at home when it happened. Your replacement will fail on you too, but you know that.

[Mudderoy]

I actually did two things. I replaced the thermostat and I washed out the transmission coolers, condenser and radiator.

I went to the car wash to do this but their change maker was out of order, so I just went home and did it with the water hose.

Temps have been around 210 going to work, and slightly above 210 (at times) going home.

I'm still going to power wash the transmission coolers, condenser and radiator.

[kryptonitexj]

thats a great idea. when I replaced the motor in my xj I had the rad. out and I pressured washed it and a LOT of mud and trash washed out of it. i was amazed. Mudderoy I would sugest removing your grill to do this it will help alot. and as always dont get to close with the pressure gun it might bent the fins. Have fun and good luck

[Jeepster19]

Did you test the new thermostat in a pot of water before installing it?If you have the old one I would reccomend you do that to so you can narrow down your problem.I have changed my thermostat&housing to a hesco hi-flow,also installed a high flow water pump from hesco and upgraded to a 3-row radiator.I think the electric cooling fan would be a likely suspect as mine went out after I fixed my a/c for no apparent reason.The new fan set me back around $75 to $100 dollars.

[Mudderoy]

Did you test the new thermostat in a pot of water before installing it?If you have the old one I would reccomend you do that to so you can narrow down your problem.I have changed my thermostat&housing to a hesco hi-flow,also installed a high flow water pump from hesco and upgraded to a 3-row radiator.I think the electric cooling fan would be a likely suspect as mine went out after I fixed my a/c for no apparent reason.The new fan set me back around $75 to $100 dollars.

Thanks for reminding me. I was going to check the old thermostat, 180 degree high flow from hesco. ;)

[BlueXJ]

Keep us informed. I hope to get my cooling system upgraded this weekend as well.

[Mudderoy]

I IR scanned my A/C condenser today (after driving about 22 miles from work). 167 on the passenger side, and 134 on the driver's side. I was a little surprised at the difference.

The transmission cooler is on the passenger side, hmmm I wonder if I'm having a mechanical fan problem. It could be that the electric fan is doing the majority of the work.

[kryptonitexj]

If you can fit it in there i would up grade to a 1997 Jeep Grand Cherokee I6 4.0 "Max cool" fan clutch. I have heard roomers that its hard to fit with 3 core rad. Heres the Link.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/partlist_Radiator-Fan-Clutch_176_R|GRPCOOLAMS__fan%20clutch___

[Mudderoy]

If you can fit it in there i would up grade to a 1997 Jeep Grand Cherokee I6 4.0 "Max cool" fan clutch. I have heard roomers that its hard to fit with 3 core rad. Heres the Link.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/partlist_Radiator-Fan-Clutch_176_R|GRPCOOLAMS__fan%20clutch___

Thanks. I read about this on some other boards, including NAXJA. Sounded like a nice upgrade.

I think it is strange that the passenger side of the condenser is 30 degrees warmer than the driver's side.

I mean the new transmission cooler is on that side, but still.

Some time back I noticed that the shroud that goes around the radiator is missnig a large piece on the passenger's side. The gap is next to the radiator. I'm thinking now that the air (as it moves faster) is going around the condenser and radiator on that side. When I slow down the fan is pulling the air over the coils. That might explain why the temp goes up the faster I go and cools down the slower I go.

I was wondering if all you guys have this shroud "bordering" the sides of your radiator?

http://xjtalk.com/images/special/Jeep_radiator4.jpg
Not a great picture, but you can see the rather large bit that is missing. I highlighted the torn edge with the yellow line.

[Mudderoy]

I went to Home Depot today (I worked until 7:30pm yesterday) and got some shower tub PVC 40 mill liner. Dark gray in color. I stuck it in that gap. I ran the engine and coolant temp got up to just below 210. I let it run awhile and it wouldn't budge in temp. Air flow seemed to be really good.

I turned on the A/C and the electric fan came on, the temp went down.

I decided to test drive it, after trying to set fire to a scrap of that PVC that I just stuffed in there. I wanted to catch fire in my hand and not in the Jeep.

Seemed ok, so I took the Jeep on a test drive. I guess it was still high 80's or hell maybe even 90 degree out at 8pm.

I got it on the highway and moved up to 75 mph quickly. I drove about 5 miles and the gauge was just a hair shy of the hash mark after 210.

I decided that was enough to tell me the PVC DIDN'T fix the problem.

I drove back at 40ish on the back roads. Temp dropped to just a hair above 210. When I got home I got my oldest daughter to rev the engine to 2000 rpm while I watched the bottom hose. I had her rev to 2000 and release, rev to 2000 and release. The bottom hose was rock steady, no movement at all.

I stopped by the autoparts and got some Water Wetter. I'm going to put it in, in the morning before I go to work, and when the coolant is much cooler.

I don't know. Something is making the coolant hotter than the cooling system's ability to get rid of the temp. It may be the water pump. It's been a couple of years, they usually only last 2 years for me.

[Mudderoy]

Okay I was just talking to a buddy here at the office. He thinks the transmission is causing the additional heat. He recommends just running the transmission off the external coolers.

I don't have a transmission fluid temp gauge, and I'm not sure the two transmission coolers I have is enough to cool the transmission.

Anyone bypass the radiator and just run on a transmission cooler? What BTU cooler are you using, and how many miles have you put on the transmission since the change?

[BlueXJ]

I doubt the tranny is putting out more heat than it used to. I am leaning toward the blades of the WP impeller being worn and not producing the same flow as it once did.
The trannies in XJs last forever. I have one setting under my workbench that went through 3 engines and has an estimated 600,000 miles or more on it and I kept it after the Jeep rusted apart.

[kryptonitexj]

I run my transmission through my after market cooler only its a 40,000 GVW one I got from Orellies it had a picture of a U-haul truck and trailer on the box.(Looks like this. Amazon.com: Hayden, Inc. 677 Transmission Oil Cooler: Automotive) WOW over kill or what,
and i also have a temp gauge. Mudderoy I recommend you get one. I got mine from egauges.com heres the like.http://www.egauges.com/vdo_ind.asp?Type=Trans_Oil_Temp&Series=Ultra_Lite&PN=ATM-4357 they also sell A pillar pods in single and dual.http://www.egauges.com/vdo_acce.asp?Subgroup=Jeep_Cherokee

Between the cooler and the gauge i love it on the freeway i run about 150 degrees in traffic Its about 180-200. Some times It spikes in traffic. I have mine mounted in front of my e fan. It cost me about $160 for the Pod, 2 gauges Air/fuel and Trans temp., and the cooler. let me know if theres anything else i can help with.

[Mudderoy]

I run my transmission through my after market cooler only its a 40,000 GVW one I got from Orellies it had a picture of a U-haul truck and trailer on the box.(Looks like this. Amazon.com: Hayden, Inc. 677 Transmission Oil Cooler: Automotive (http://www.amazon.com/Hayden-Inc-677-Transmission-Cooler/dp/B000C3F3SO/ref=pd_lpo_k2_dp_k2a_1_img?pf_rd_p=304485601&pf_rd_s=lpo-top-stripe-2&pf_rd_t=201&pf_rd_i=B000C39C9A&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0CQ6J797N17A3290036H)) WOW over kill or what,
and i also have a temp gauge. Mudderoy I recommend you get one. I got mine from egauges.com heres the like.http://www.egauges.com/vdo_ind.asp?Type=Trans_Oil_Temp&Series=Ultra_Lite&PN=ATM-4357 they also sell A pillar pods in single and dual.http://www.egauges.com/vdo_acce.asp?Subgroup=Jeep_Cherokee

Between the cooler and the gauge i love it on the freeway i run about 150 degrees in traffic Its about 180-200. Some times It spikes in traffic. I have mine mounted in front of my e fan. It cost me about $160 for the Pod, 2 gauges Air/fuel and Trans temp., and the cooler. let me know if theres anything else i can help with.

Thanks I installed the B&M transmission cooler about a month ago now. Same physical dimensions as your Hayden. I mounted it in front of the mechanical fan (cooler, condensor, radiator). I want the gauge but I do not have the money for any extras right now. I need to fix the running hot problem so any money I have will have to go to that.

I may look and see how much work it would be to bypass the radiator this weekend and just run through the transmission coolers. (I have two, OEM and the B&M).

I can tell that the Jeep mechanic that I am working with online suspects the fan clutch.

[Mudderoy]

I doubt the tranny is putting out more heat than it used to. I am leaning toward the blades of the WP impeller being worn and not producing the same flow as it once did.
The trannies in XJs last forever. I have one setting under my workbench that went through 3 engines and has an estimated 600,000 miles or more on it and I kept it after the Jeep rusted apart.

My AW4 feels very solid. Doesn't do anything that I have expected it to do for the last 11 years. I wish I had a gauge on the transmission fluid so I could see what is going on there. Of course with the engine coolant running hot, the transmission fluid is going to be hotter as well. May get a false transmission fluid reading because of it.

[xjjeepthing]

Mud maybe you need to move your trans cooler to a different location on the rad

[Mudderoy]

Mud maybe you need to move your trans cooler to a different location on the rad

I have considered it. I picked up a HD fan clutch from NAPA on the way home. It is for a Grand Cherokee, but is supposed to fix the XJ.

The tech that I am working with online is having me do testing of the mech fan and it isn't doing something it is supposed to do. I jumped the gun a little bit, but I've been concerned that the clutch has been a problem for awhile.

I'm waiting for the Jeep to cool down then I'm going to go install it.

Hey do you have to BURP your cooling system? I get the feeling this is only something you have to do on the pre 96/97 models.

[kryptonitexj]

you only have oburp it if you open it. its suppose to burp its self trough the rad cap.

[Mudderoy]

Heavy Duty Grand Cherokee fan clutch installed.

Ran just over 210 on the highway at 70-75 mph. Cooled down a hair going 65 mph. (2800 rpm and 2500 rpm).

I'll have a better idea tomorrow about 3pm.

One negative. It screams! It makes a screaming noise once it gets to a certain RPM, about 2900 rpm.

[BlueXJ]

So are you saying that the NEW fan clutch accomplished zero??

[Mudderoy]

So are you saying that the NEW fan clutch accomplished zero??

I am seeing a significant difference, but the most I'll say right now is "hopeful". Driving at night in the cool 88 degree temp :rotfl2: at highway speeds is one thing. Doing it during the day when it is 100 degrees out will be the real test.

The other night I went for a drive at 9pm and the temp was at the first hash after the 210 in 5 miles. Tonight I drove, ahhh 10 miles, and the temp was just above 210. It isn't where I want it, and I still think you are correct about the water pump.

The really surprising thing, to me, is the clutch fan made a big difference driving at speeds that I was told it wouldn't make any difference.

Now do I have another problem and the Heavy Duty fan clutch is helping make better? I think so. If I replace the water pump and I don't see 210 temps most of the time, I suspect I have a leak somewhere in the head.

My decision is do I want to go with another OEM style water pump or get a high flow.

Now that I have bought the HD fan clutch I wish I had gone ahead and bought an electric fan to replace the mechanical.

[BlueXJ]

That is my plan. I have been gathering stuff to do the conversion to all electric fans and no FC. I have a brand new 3 row all metal radiator and a brand new curved blade fan. I have read a few writeups on the conversion and hope to attempt it by next week sometime. I bought a SPAL electric fac controller and it will allow the new fan two speeds which are thermostaticly controlled. slow to come on at 190* and high at 210*. Hopefully high will run very little. And we always have the OEM A/C fan as well.

[Melissa]

I am really interested in whats going on with your temps Mudderoy and following this thread very close, thank you for keeping it updated with your progress!

[Mudderoy]

That is my plan. I have been gathering stuff to do the conversion to all electric fans and no FC. I have a brand new 3 row all metal radiator and a brand new curved blade fan. I have read a few writeups on the conversion and hope to attempt it by next week sometime. I bought a SPAL electric fac controller and it will allow the new fan two speeds which are thermostaticly controlled. slow to come on at 190* and high at 210*. Hopefully high will run very little. And we always have the OEM A/C fan as well.

I was reading last night that the mechanical fan is a 4000 cfm fan whereas the electrics only approach 3000 cfm. The Taurus 2 speed fan will do 4000. So it seems the best idea for going to an electric fan is to replace them both. That way you have cooling over the entire radiator and they both come on or go off depending on the temp. I like the idea, just not the price. That's about $300. The write up on GO JEEP seems to be the best I found so far.

Basically for me if I had gone to an electric fan I may have seen the same results as my stock mech fan, or INCREASED coolant temps. I would have been pissed having the put the mech fan back on until the summer was over.

[kryptonitexj]

it's sounding more and more like a cracked head. Hey mudderoy Ive got a compression tester in my tool box if you wanna barrow it to check comp on all cylinders. By the way what casting is your head?

[Mudderoy]

it's sounding more and more like a cracked head. Hey mudderoy Ive got a compression tester in my tool box if you wanna barrow it to check comp on all cylinders. By the way what casting is your head?

I've never had a head problem with the Jeep before, but I had one with a V6 on a 85 Cougar. If it is a cracked/warped/blown gasket it is very very mild.

I think I'm going to replace the water pump tomorrow.

[BlueXJ]

I've never had a head problem with the Jeep before, but I had one with a V6 on a 85 Cougar. If it is a cracked/warped/blown gasket it is very very mild.

I think I'm going to replace the water pump tomorrow.


I am looking forward to your report on that installation and the improvement in your Jeep's temperature.
Why not take a series of pics while doing this and making a writeup on WP replacements so we can have that for folks who have never done this before?
Kill two buzzards with one rock so to speak.

[Mudderoy]

I am looking forward to your report on that installation and the improvement in your Jeep's temperature.
Why not take a series of pics while doing this and making a writeup on WP replacements so we can have that for folks who have never done this before?
Kill two buzzards with one rock so to speak.

I tried to buy the water pump Saturday while I was getting the tranny filter, but they only had one and it was WRONG. That's good because I decided instead of spending $40 on an OEM style I'll just get the "flow kooler high flow water pump". The water pump I bought has a lifetime warrenty and yes I have the receipt! I'll take the old one off, but it in the box and get a FREE OEM replacement. So I'll have two. the HIGH flow and a regular.

I changed the transmission fluid, boy as hot as it was outside I'm glad I didn't choose to do two things to the Jeep.

[Mudderoy]

Ok I just ordered the Flowkooler 1747 water pump. Summit had it for $112.69 but Quadratrek had it for $99.99, $114 shipped.

I read this on summit...


Get 30 percent extra coolant flow.
Flow Kooler water pumps solve low-speed heating problems by doubling the water flow rate at low rpm and idle. At 3,500 rpm, the flow rate returns to normal, to prevent too much water flow at high speeds. These pumps also last longer than a stock replacement. They use a specially designed steel plate on the impeller that traps water, eliminates cavitation, increases flow, and reduces engine temperatures.

:link: (http://summitracing.com/parts/BRA-1747/)

I don't have a low speed heating problem, but hey it can't hurt right? :driving:

Now if I can get motivated, I mean really motivated I can get my new front shocks installed, disc brake pads installed, and replace the water pump this up coming 3 day weekend.

Oh and I still have to get 20+ envelopes stuffed with stickers and addressed to be mailed out.

[Mudderoy]

Well it finally happened. I drove all the way to work in 80+ degree air temps and the coolant never got above 210! :thumbsup: I punched it a few times to purposely increase the coolant temp. I drive a section that is about 50 to 60 mph. Even after it got to 210, after a few minutes I checked and it was back to just a hair below 210 (needle still on the 210 mark). That's the coolant sweet spot that we all know an love, well at least me since that is where it was for the first 9+ years of driving.

It will be interesting to see what it does this afternoon. Air temps may be 20 degrees hotter.

The fan clutch made a difference, but now I'm starting to think the transmission fluid may have been the culprit!!!

[Melissa]

Ok I just ordered the Flowkooler 1747 water pump. Summit had it for $112.69 but Quadratrek had it for $99.99, $114 shipped.


If you don't mind me asking, what was the total you paid with shipping from Summit?

[Melissa]

The fan clutch made a difference, but now I'm starting to think the transmission fluid may have been the culprit!!!

How can transmission fluid be the culprit???

[Mudderoy]

How can transmission fluid be the culprit???

I don't know, it is the last thing I changed before I saw this change.

If you think about it automatic transmission fluid does a couple of things. It helps create pressure that allows the bands to be engaged. It also creates cooling of those bands. If the bands slip, and they always do, they create heat. The less slipping the less heat. The better the ability of the fluid to carry away the heat, the less slipping. Like I said I don't really know, I'm just thinking.

[Mudderoy]

If you don't mind me asking, what was the total you paid with shipping from Summit?

You're a nosey little thing aren't you? :p

1 71212 100 FLOWKOOLER MOST JEEP 4.0L CHEROKEE 1747 99.99

Total $: 99.99
__________________________________________________ ________________________________________
Order Recap:
Total Product $: 99.99
Net Product$: 99.99
Shipping: 14.99
Sales Tax: 0.00
Grand Total: 114.98
__________________________________________________ ________________________________________

[Melissa]

You're a nosey little thing aren't you? :p


Well of course :D

I asked cause I wanted to know wich water pump to add to my list to order on the first of July.

I made the huge mistake when I sold my old motor, I did not realize that when my donor motor was swapped that my mech did not switch over the brand new water pump, thermostat and thermostat housing that I had just put on the old motor, so I am changing these things on the donor motor and I decided that I wanted a better water pump ;)

Is it a good idea to change the tranny fluid? I have never had this done as far as I know. I did hear that if you do, sometimes that will cause your transmission to fail :smiley-scared002:

[Mudderoy]

Well of course :D

I asked cause I wanted to know wich water pump to add to my list to order on the first of July.

I made the huge mistake when I sold my old motor, I did not realize that when my donor motor was swapped that my mech did not switch over the brand new water pump, thermostat and thermostat housing that I had just put on the old motor, so I am changing these things on the donor motor and I decided that I wanted a better water pump ;)

Is it a good idea to change the tranny fluid? I have never had this done as far as I know. I did hear that if you do, sometimes that will cause your transmission to fail :smiley-scared002:

Well (if you read my write up) you'd see that is why I didn't replace all the fluid with new fluid. I went for a 50/50 mix, but ended up favoring the new. Maybe 60/40 or 70/30. Of course that is just the 4 quarts that comes out when you drop the pan.

If you can afford it get the hesco high flow water pump. I couldn't afford the $169 plus shipping for it. That is the one I wanted, but $100 is a little more realistic for a water pump I think.

[Mudderoy]

I installed the flowkooler water pump today. It gets pretty easy when you've done it, ahhh, 6 times now.

Anyway no change. The biggest change has been the addition of the HD fan clutch. It feels pretty hot out there today, 100 I though, but no 94.

At 65 mph (2500 rpm) I run about 215 degrees with the A/C on. Running at 75 mph (2800 rpm) I get close to 222, say 219 with the A/C on.

If I turn the A/C off and run 75 mph my temp drops about 10 degrees back to 215.

Sitting in the driveway it drops to about 212.

I have a 3 core all metal radiator. A heavy duty fan clutch, and now a high flow water pump. All the hoses are new.

I need to double check the coolant levels to make sure it's not low. I filled the radiator, waited for the thermostat to open. The level dropped dramatically at about 180 degrees, and I continued to fill until it was full to the top. The overflow bottle had the right level in it, so I'll have to see if it drops, or empties. If it does then I'll know that my coolant level was low during the test.

I MAY have a lower hose collapsing on me. I checked this but it was dark and really I just watch to see any movement from the hose.

I MAY have a head gasket issue, a warped or cracked head. It must be pretty minor if that is the case.

I am also wondering if I have a A/C issue. It certainly makes a big difference with the A/C on or off. 222 - 10 is 212, which is pretty close to that magic 210 number.

I'm going to hook the laptop up to it tomorrow and record some data.

[Mudderoy]

Is there anything that will flush a radiator, I mean really get the crap out that may be built up inside?

My coolant is very green and pretty and hasn't changed in a couple of years, but prior there was red mud in there. I wonder if it is caked up somewhere causing a flow issue.

Do they sell anything that will break up this crap?

[BlueXJ]

The only real solution is to have a radiator shop disassemble it and "rod" it out. That is a real cleaning and most shops will guarantee their work.

[Mudderoy]

The only real solution is to have a radiator shop disassemble it and "rod" it out. That is a real cleaning and most shops will guarantee their work.

But it is a NEW radiator. As in 9/3/2008 :confused:

Besides I'm thinking it's got crud in the head and maybe in the block.

[Mudderoy]

By the way. I took a close look at the flowkooler water pump. It looks almost identical to the $40 pump from OReilys. The only difference "I NOTICED" was a metal disk riveted to the stock "looking" impeller. The metal disk had a hole in the middle, so it's kind of a flat donut metal disk.

So buy you a stock water pump, rivet a metal donut to it and sell them for $75. That's $25 cheaper than the flowkooler. You'll make a $35 profit on each one! :rotfl2:

[Melissa]

By the way. I took a close look at the flowkooler water pump. It looks almost identical to the $40 pump from OReilys. The only difference "I NOTICED" was a metal disk riveted to the stock "looking" impeller. The metal disk had a hole in the middle, so it's kind of a flat donut metal disk.

So buy you a stock water pump, rivet a metal donut to it and sell them for $75. That's $25 cheaper than the flowkooler. You'll make a $35 profit on each one! :rotfl2:

Next time would you just buy the stock water pump?

I am asking cause I can not afford the hesco water pump at this time and was going to get the flowkooler, should I still??

[Mudderoy]

Next time would you just buy the stock water pump?

I am asking cause I can not afford the hesco water pump at this time and was going to get the flowkooler, should I still??

I might need a few days to fully be able to tell any difference. From what I have seen I could have left the old water pump in.

[Melissa]

I might need a few days to fully be able to tell any difference. From what I have seen I could have left the old water pump in.

Okie dokie, let me know what you think in a few days then please :)

[Mudderoy]

Ok so today I bypassed the heater core. I didn't think a leaky heater core would cause the engine to run hot, but what the hell.

I changed to a Robertshaw 195 degree thermostat, high flow mama!

Took it out on the highway, it may be running 5 degrees cooler but that could be because it is 92 degrees air temp instead of 97 like it was when I tested it the other day.

I MUST have a clog in the water pathway somewhere. The only thing left is the electric fan.

[Mudderoy]

I broke out the ODB II scanner yesterday and hooked it up to the laptop to run that multiple RPM level test that E-mike mentioned.

Here's the readers digest version.
Robertshaw 195 degree thermostat installed.
Heater core bypassed (suspect leak)
A/C off. Test was doing sitting still and at 7pm yesterday. Air temps in the low to mid 90's.

I let it idle and get to operating temp, 210 according to the scanner.
18:15.9 Engine Coolant Temperature 210.2 deg F
18:16.3 Engine RPM 855 rpm
18:16.7 Intake Air Temperature 150.8 deg F

Throttled up to 1000 rpm (about 1000 hard to hold it)
19:46.7 Engine Coolant Temperature 212 deg F
19:47.1 Engine RPM 912 rpm
19:47.5 Intake Air Temperature 158 deg F

Throttled up to 1500 rpm for 1 minute
21:08.9 Engine Coolant Temperature 212 deg F
21:09.4 Engine RPM 1548.25 rpm
21:09.8 Intake Air Temperature 163.4 deg F

Throttled up to 2000 rpm for 1 minute
22:07.7 Engine Coolant Temperature 210.2 deg F
22:08.2 Engine RPM 1919 rpm
22:08.5 Intake Air Temperature 167 deg F

Idled for 1 minute
23:09.5 Engine Coolant Temperature 217.4 deg F
23:09.9 Engine RPM 802.75 rpm
23:10.3 Intake Air Temperature 174.2 deg F

Throttled up to 2500 rpm for 2 minutes
25:09.4 Engine Coolant Temperature 213.8 deg F
25:09.8 Engine RPM 2466.25 rpm
25:10.2 Intake Air Temperature 177.8 deg F

After throttle up test, I just let it idle and watched the 3 measured indicators.
After 3 to 5 minutes it reached this level.
At which point the electric fan turned on...
26:07.7 Engine Coolant Temperature 222.8 deg F
26:08.1 Engine RPM 837.5 rpm
26:08.5 Intake Air Temperature 183.2 deg F

The fan shut off here
28:29.9 Engine Coolant Temperature 215.6 deg F
28:30.3 Engine RPM 779.75 rpm
28:30.7 Intake Air Temperature 188.6 deg F

32:17.3 Engine Coolant Temperature 224.6 deg F
32:17.7 Engine RPM 864 rpm
32:18.1 Intake Air Temperature 190.4 deg F

After seeing the cooling temp fall VERY slowly after the electric fan turned on I suspected it, I replaced it, but it did not resolve the problem.

I reconnected the heater core. Put a air block at the base of the condenser/radiator. Drove to work today in mid 80 degree air temps and temp held about 212. This is normal for morning driving, but afternoon coolant temps are in the 230 degree range. I originally thought it was approaching 222 based on the dash gauge, however I found that 222 is just about a needles width past the 210 mark. About a needles width before the first hash mark after the 210 is 230, at least according to the coolant temp sensor and direct readings using the OBD II scanner.

[Melissa]

So you have done a upgraded radiator, thermostat, water pump and both fans?

Whats left??

[Mudderoy]

So you have done a upgraded radiator, thermostat, water pump and both fans?

What left??

Heater core.
Remove transmission from radiator.
Based on the data above it doesn't seem to be a transmission heat problem.

Even though the efan is pulling a LOT of air from the front it doesn't seem to cool the coolant down very quickly. I would expect something that covers 1/2 of the radiator to do much more cooling.

So a maybe the NEW radiator is defective, or has a clog. I was still having the running hot situation with the 2 core, the 1st 3 core, and the 2nd 3 core. This is why I haven't done anything else with the radiator.

[firehawk]

I'm curious if those temps are "normal" for an XJ sitting still with no airflow thru the radiator other than the fans.:confused: As I've said before, there is no were for the heat to go especially while sitting still. BTW, was the hood closed while doing the test? If it was, I wonder what results you'd get with it open?

Hood vents baby!!!:thumbsup: I DO recall seeing a export version of the XJ, and it had vents in the hood towards the front corners. They were over the battery, and airbox areas. It made sense to me since the fans are blowing air up in those areas.

[Melissa]

Heater core.
Remove transmission from radiator.
Based on the data above it doesn't seem to be a transmission heat problem.

Even though the efan is pulling a LOT of air from the front it doesn't seem to cool the coolant down very quickly. I would expect something that covers 1/2 of the radiator to do much more cooling.

So a maybe the NEW radiator is defective, or has a clog. I was still having the running hot situation with the 2 core, the 1st 3 core, and the 2nd 3 core. This is why I haven't done anything else with the radiator.



When you say remove the transmission from radiator, do you mean make both your OEM and B&M tranny coolers stand alone, or get rid of one all together?




I'm curious if those temps are "normal" for an XJ sitting still with no airflow thru the radiator other than the fans.:confused: As I've said before, there is no were for the heat to go especially while sitting still. BTW, was the hood closed while doing the test? If it was, I wonder what results you'd get with it open?

Hood vents baby!!!:thumbsup: I DO recall seeing a export version of the XJ, and it had vents in the hood towards the front corners. They were over the battery, and airbox areas. It made sense to me since the fans are blowing air up in those areas.



If I recall I believe Spanky said that the spot to put hood vents was also down around the radiator area, I remember reading that somewhere on this board and I believe Spanky was the one that said it.

[Mudderoy]

I'm curious if those temps are "normal" for an XJ sitting still with no airflow thru the radiator other than the fans.:confused: As I've said before, there is no were for the heat to go especially while sitting still. BTW, was the hood closed while doing the test? If it was, I wonder what results you'd get with it open?

Hood vents baby!!!:thumbsup: I DO recall seeing a export version of the XJ, and it had vents in the hood towards the front corners. They were over the battery, and airbox areas. It made sense to me since the fans are blowing air up in those areas.

Well I have the information posted on a thread at NAXJA. There is a local XJ guy that had a good idea. I need to run the same test on a XJ that is working correctly. I went to a local 4x4 website and put out a request for 15 minutes of time with their 1998 XJ. If I can find one here locally and run the same test, maybe it will give me a clue.

The hood was closed.

I thought I had found the problem so I didn't think about running an open hood test. Maybe I'll do that when I get home.

I got a check engine light on the way to work this morning. Very rare to see that on my Jeep. I'm hopefull the code will be a detailed explaination as to why it is running hot. :rotfl2:

[Mudderoy]

When you say remove the transmission from radiator, do you mean make both your OEM and B&M tranny coolers stand alone, or get rid of one all together?







If I recall I believe Spanky said that the spot to put hood vents was also down around the radiator area, I remember reading that somewhere on this board and I believe Spanky was the one that said it.

Just run it through the tranny coolers, not through the radiator.

[Mudderoy]

Anyone have any experience with IR scanners and measuring the coolant temp? I'm seeing a 15, perhaps more, degree difference between the measured temp from the sensor, and the IR scanner. 15 degrees lower on the IR scanner.

[Mudderoy]

I found some really good diagnostic information using a IR scanner.

:link: (http://www.aa1car.com/library/tstemp.htm)

[muddeprived]

Well I have the information posted on a thread at NAXJA. There is a local XJ guy that had a good idea. I need to run the same test on a XJ that is working correctly. I went to a local 4x4 website and put out a request for 15 minutes of time with their 1998 XJ. If I can find one here locally and run the same test, maybe it will give me a clue.

The hood was closed.

I thought I had found the problem so I didn't think about running an open hood test. Maybe I'll do that when I get home.

I got a check engine light on the way to work this morning. Very rare to see that on my Jeep. I'm hopefull the code will be a detailed explaination as to why it is running hot. :rotfl2:

It will say : P0000 Texas stated deemed too hot. Move to Alaska necessary.

I think we know what that code means.

[Mudderoy]

lol, actually it was a P0305 misfire on cylinder 5. I reset it and it hasn't come back.

[muddeprived]

lol, actually it was a P0305 misfire on cylinder 5. I reset it and it hasn't come back.

I get the misfire cyl #3 code every couple months. sick of it.....

[Mudderoy]

I noticed the other day while installing the HD fan clutch that my fan was further away from the top of the radiator than the bottom, and none of the fan is within the shroud.

I thought about this and figured that the reason there is a tilt to the fan is because of the 1" transfer case drop.

I never had a running hot problem on the freeway until I installed the kit, and the 1" TC drop.

Maybe I should have spent my bushwacker money on a SYE.

[Mudderoy]

Jeep overheat problem has been solved. I need to highway test it to be 100% sure, but the driveway test RPM test has temp varying from 210.2 to 220.5. Runs about 217 sitting in the driveway, creeps up to 220.5 and the efan kicks on, and temp drops to 215.4 and efan kicks off.

A/C on holds 217 at idle, run up to 2200 rpm temp drops to 210.2 and holds.

[firehawk]

Jeep overheat problem has been solved. I need to highway test it to be 100% sure, but the driveway test RPM test has temp varying from 210.2 to 220.5. Runs about 217 sitting in the driveway, creeps up to 220.5 and the efan kicks on, and temp drops to 215.4 and efan kicks off.

A/C on holds 217 at idle, run up to 2200 rpm temp drops to 210.2 and holds.

What a teaser post.:rotfl2: What fixed it?:confused:

[BlueXJ]

What a teaser post.:rotfl2: What fixed it?:confused:


Firehawk that is the way Muddy is. He will tease you and claim he answered the question in another thread. Very frustrating. If he didn't own the site I would give him a 3 day ban for treating members badly.

[Mudderoy]

Oh! Didn't I say?!?!? rofl

Sorry you'll have to buy the book!

[Melissa]

Now thats not nice, I want to know too.

Pretty please Muddy :innocent0002:

[Mudderoy]

BTW, I just got back from a 18 mile test run. It was dark and the temps outside were cooler, but the Jeep still runs hot at 75 mph. It's fixed. Needle never got off the 210 mark. :smiley-gen165:

[Mudderoy]

First off I'll tell you a dirty little secret. The gauge LIES to you.

I'm assuming this is the same for everyone since everyone KNOWS about the magical 210 number.

Watching my laptop that was connected to the OBD II scanner and watching the temp gauge I found this out.

From where the needle touches the 210 hash mark on the left, to where it touches it on the right had side is 205 degrees to 220 degrees!!!!!

When I got home today I TORE the garage a part looking for the old temp sensor, why you may ask?

Well as I stated earlier I got to work and it was on 210. I IR scanned it and it said 195, thats a ****ing 15 degree difference! I asked a guy at work that knows a lot about cars, and he says there are 3 different grades of parts.

Specifically the temp sensors are 1%, 5% and 10%. The 1% is what you buy from the dealer for $85, the 5% and 10% are what you get from the auto parts for $28.

So after an hour or so, I found the original little bastard and installed it.

The resolution to my running hot problem? I DON'T KNOW!!!! I fixed it with something, but the temp sensor and gauge were LYING TO ME!!!!!

It's ok, I'm still happy. I ran down the highway 9 miles 75 mph, 2800 rpm and it never got off the 210 (hell it may have been 220 in reality, but I didn't know it!) On the way back I drove 65 mph, 2500 rpm, and the temp dropped just a tad below center of the 210 hash mark. Just where God intends!

If I didn't have the high tech tools, the IR scanner and the OBD II scan tool I probably wouldn't have figured it out.

I still need to drive in the 100 degree heat, but my basic problem that I have had for 2+ years has been resolved.

[Melissa]

So the moral is to spend the extra $$ and go for the dealer temp sensor

[Mudderoy]

So the moral is to spend the extra $$ and go for the dealer temp sensor

A ham buddy of mine who's done fleet maintenance for Harris county for 30+ years told me to always buy OEM replacements.

I'd still be hard pressed to buy a $85 temp sensor, assuming they really cost that much, so I'd say the moral to this story is don't change the thing you are using to identify the problem. I should have verified the sensor was a problem before replacing it, then I needed to verify the replacement was working correctly. Fail and Failed!

You know this goes right back to my MPG issue. I've been told to replace the O2 sensors, with OEM. I guess this is my lesson.

[Melissa]

Mine to, now I know the steps I need to take on mine, thank you for your trials and errors, I appreciate it very much

[BlueXJ]

So you fixed nothing but corrected your first error.

[Mudderoy]

So you fixed nothing but corrected your first error.

No there was a problem with the Jeep running hot. In my attempt to fix it I changed the measuring device, the temp sensor. This threw off what I was using to SEE if the problem was fixed. So I kept changing things. One of those things FIXED the running hot problem, but since my measuring device was wrong I don't know what fixed it.

Now that I have gone back to the original measuring device I can see that the original problem has been solved.

I suspect that I fixed the problem over a year ago with the 3 core and the water pump that went out shortly after installing the 3 core. I think my most recent problem with the over heat at midnight was probably the fan clutch, or the e-fan not coming on as you suspected.

[Mudderoy]

lol, actually it was a P0305 misfire on cylinder 5. I reset it and it hasn't come back.

P0305 has come back. Everything running great, and strong. Hmmm I'm thinking injector. Maybe this is the answer to my MPG issue.

[Melissa]

P0305 has come back. Everything running great, and strong. Hmmm I'm thinking injector. Maybe this is the answer to my MPG issue.

Ok school me................what do injectors do? How do they fail?:)

[Mudderoy]

Ok school me................what do injectors do? How do they fail?:)

A while back engines used carburetors. The carburator sat on top of the air intake manifold. The "jets" in the carburetor would spray gasoline into the opening of the bottom of the carburetor and it would then pass into the air intake. This would be mixed with air and be sucked into the camber between the piston and head. It got there because of the vacuum created by the piston moving down the cylinder and that intake valve opening.

So basically you had 2(?) jets in the carburetor servicing 6, 8, etc... cylinders. 1 for each side of the engine on the V8.

Fast forward a few years and the carburetor was replace with (I guess it would be called) a throttle body. The throttle body still sat on the air intake but now it had two injectors sitting on top of it. The injector would also spray gas into the two sides of the throttle body (in a V8) but now it was being controlled by a computer, and the injectors were digital. Open or closed. Precis control could now be had, and this improved fuel economy.

You still had the problem with two injectors servicing many cylinders.

Fast forward a bit more and now they have a injector per cylinder. The computer "knows" when the right time to send the signal to the specific cylinder and how long to keep the injector open to deliver just the right about of fuel.

As time, and wear sets in the injectors (being mechanical devices) may be slow to open. Not open all the way. Get clogged. Start leaking. I think the computer an figure out some of this stuff based on the O2 sensors, but remember the O2 sensors are "seeing" whats is happening with ALL the injectors not just a specific one.

Basically the computer could see a fuel "rich" environment because of ONE leaky injector (leaking fuel into the chamber) and it would adjust the ENTIRE engine, not just that one injector. Fuel economy goes down.

From what I have read the injectors we have in our 4.0L have 2 holes in the bottom. The have 4 hole replacements, that deliver a more even spray and since the injector plugs directly into the cylinder it is servicing this better spray pattern helps improve the efficenty of the combustion. This improves fuel economy.

I've been wanting to replace my injectors for awhile now. But they are $200 for 6 and I've already thrown a bunch of parts at problems without figuring out what the problem is exactly. I'm in a catch 22 situation. I need to buy some diagnostic devices, but they are pretty expensive as well. Fuel pressure gauge is $35 for example. That gauge isn't going to fix anything, and putting that $35 towards some new injectors I think would be better.

I mean new injectors might not solve a problem but they will improve the engine overall. Just like the 99+ air intake. It doesn't solve a problem, but it will improve horse power and miles per gallon because of a better design.

Now my background is computers, not automobiles. I've only had some experience with 60's, 70's, 80's V8 engines (chevy) and the 4.0L I have now. I am basing the information above on that experience and all that I have read. So someone else feel free to come in here and add to or flat a$$ correct me. :D

[Melissa]

WOW, thanks for the information!! I know my ex-husband made sure that when we bought my suburban it was the last year that had a carburetor, before they went to the throttle body. He said it was easier to work on. So are our injectors easy to work on, or a pain in the a$$.

[Mudderoy]

WOW, thanks for the information!! I know my ex-husband made sure that when we bought my suburban it was the last year that had a carburetor, before they went to the throttle body. He said it was easier to work on. So are our injectors easy to work on, or a pain in the a$$.

Someone else can correct me if I am wrong, but you take out the injector and put in the new one. The just pop out and pop in. The fuel rail is bolted to the intake which helps hold them in place.

I think a carburetor is much more complicated, but really isn't it what you know that makes things easy? When I built my Chevy 327 the carburetor was really easy. I just bought a 600 cfm Holly straight bore and bolted it to the Eldelbrock intake.

[4.3LXJ]

Someone else can correct me if I am wrong, but you take out the injector and put in the new one. The just pop out and pop in. The fuel rail is bolted to the intake which helps hold them in place.

I think a carburetor is much more complicated, but really isn't it what you know that makes things easy? When I built my Chevy 327 the carburetor was really easy. I just bought a 600 cfm Holly straight bore and bolted it to the Eldelbrock intake.

Hollys can work well out of the box. But to really make them work, that is a science that dwarfs fuel injection. Try tuning a Weber side draft, that is even worse.

[Mudderoy]

Hollys can work well out of the box. But to really make them work, that is a science that dwarfs fuel injection. Try tuning a Weber side draft, that is even worse.

lol I can put things together but I really only "work" on it when I have to. I much prefer the playing (driving). It was years ago when I did all that with the 327, so I'm sure I'm only recalling the "fun" stuff. I know there was some adjusting I had to do. The mechanical kick down I do remember adjusting.

[Melissa]

I have heard that carbs are now pretty much a thing of the past and are getting harder and harder to find plus more expensive, true or is someone just blowing smoke up my arse?

[muddeprived]

WOW, thanks for the information!! I know my ex-husband made sure that when we bought my suburban it was the last year that had a carburetor, before they went to the throttle body. He said it was easier to work on. So are our injectors easy to work on, or a pain in the a$$.

somewhat of a PITA but still easy to work with. You have to disconnect a bunch of stuff, unbolt the fuel rail, release the fuel pressure, pop off the fuel rail (watch all the gas go everywhere) and then you got access to the injectors. Kinda sucks to have to take off the entire rail just to service one injector but most people replace them all at once anyways.


Mudd, my injectors have 1 hole but I replaced them with 4-hole ford injectors. Do some come with 2-holes?

You might want to run a can or two of seafoam in your tank and intake to clean everything out. Maybe the injectors are dirty. Never hurts to try and you get a good cleaning from it too.

[pvt.Tadpol xj]

Hey guy Scottyadd here. I had a strange problem with my dash gauge recently and started checking out everything to. But I knew it could not be anything critical so when I removed the plug from my coolant temp sensor for the 5th time one of the two wires poped out of the plug so I stripped a tiny bit of insulation off and seated the wire very well back into the plug and pushed a toothpick down in there a little bit and broke it off and everything tuned itself back up. I could be wrong about your ride, but I hope this will help. Good Luck......

[Mudderoy]

http://xjtalk.com/images/special/jeeptempGauge2.jpg

Ok after all the upgrades to the cooling system this is the normal operating temperature when it's about 75 degrees air temp! :rotfl2:

[Mudderoy]

Well I hate when things like this happen, but I am grateful when things go right instead of wrong.

Now the outside air temps have been 60's, 70's, but that didn't matter in the past, but I have noticed that driving on the highway at 80, 85, 90 mph my engine coolant temps are staying just below that magical 210!

I went to Baytown recently, fully loaded, and I guess it was 72 degrees out. That's about 50 miles from Katy. I think we averaged 70 mph (wife was with me) while on the highway. Temps were well below 210, about where the needle is in the picture above.

I went to Spring Creek Off Road, which is about a 45 minute drive, mostly highway, and I didn't see 210 until I was on the trail. I was getting a little concerned that the off road wheeling was going to put me over the 210, but know, apparently it got hot enough for the electric fan to kick on and next I checked the temp was well below the 210 mark.

I need to get my switch panel done and wire up a switch for the electric fan.

So the FlowKooler water pump may have made the difference. I still want to get that cowl induction hood so I can get rid of the under hood heat, but at least now I have a few months.

[Silly Willy]

...I've been wanting to replace my injectors for awhile now. But they are $200 for 6 and I've already thrown a bunch of parts at problems without figuring out what the problem is exactly. I'm in a catch 22 situation. I need to buy some diagnostic devices, but they are pretty expensive as well. Fuel pressure gauge is $35 for example. That gauge isn't going to fix anything, and putting that $35 towards some new injectors I think would be better.

.... This was a long quote

That is the beauty of Autozones rental program. Basically buy the item, then return it. That's what I do.

[BlueXJ]

Buying tools is not an expendature but an investment, because you will use it time and again over the years. I have still got a compression tester I bought back in the 60s and used it just last week. Probably have used it on 50 vehicles over the years. $15 well spent IMHO

[Mudderoy]

Buying tools is not an expendature but an investment, because you will use it time and again over the years. I have still got a compression tester I bought back in the 60s and used it just last week. Probably have used it on 50 vehicles over the years. $15 well spent IMHO

I still have the compression tester I used on my 327 back in ahhh 1978(?) but the hose is missing!!!! :rotfl2:

[muddeprived]

I finally found the answer I think. There's a guy on my local 4wd hardware forum that did an electric fan conversion and he dug up the info during his project.

The stock fan ('97 & up) is;
Bosch GPB 12v 13.5Amps
12" dia x 3.25" depth

Flow;
.25 Cubic Meter Per Sec
900 Cubic Meter Per Hour
530 Cubic Foot Per Minute

So the factory fan is 530 CFM. If this is true I'll aim for a 750-1000 cfm fan.

[Mudderoy]

I recently drove 1+ hour to Creekside. Air temps were mid 90's. At 65 mph coolant temp was well above 210 and very near the first hash mark after the 210 hash.

When I slow to 30 to 40 mph the coolant temp drops to just above 210. It takes about 5 minutes for it to drop. The cooling system seems to be working very well even in the high air temps, but only if my RPM is in the 1500 to 1700 range.

I forgot about doing the compression test. I guess I should do that.

[Mudderoy]

I was doing some reading about running hot at highway speeds and I came across something that I had forgot about. The lower hose collapse issue. There is a discussion about the spring in the hose or no spring in the hose. Some say that the newer replacement hoses are thicker and don't need the spring others say you do.

When I replaced the lower hose, a couple of times now, I moved the spring to the new hoses. I'm wonder if perhaps the spring is in the wrong place or is no longer strong enough to hold the hose open.

Couple that with the high flow thermostat, high flow thermostat housing and high flow water pump.... well...

So I called the local Jeep/Chrysler dealer. They found the lower hose and told me $21, but they'd have to order it. I asked if it came with the spring, and he couldn't tell me since the computer screen didn't say. The hose was at another Houston area dealership, so I called over there.

This guy asked if I had a 4 wheel drive, which the other guy didn't ask. Turns out the 4 wheel drive hose is $71 whereas the 2 wheel drive hose is $21. He wanted the last 8 to my VIN to make sure it was the right hose before order it for me. Since I was driving I told him I'd call him back.

Why would they have two different radiator hoses for a 1998 Jeep Cherokee with a $50 difference because one was a 4x4? I mean if they are treating 4x4 like "plane" or "boat" then I understand. Unless there is something radically different about the hoses.

[pingpong]

there is no difference between the 2wd hose and the 4wd hose.. he was trying to :smiley-laughing021::smiley-laughing021: you get the idea. The radiator and engines are the same from the 2wd and the 4wd so why would there be a different hose:shocker:

[Mudderoy]

there is no difference between the 2wd hose and the 4wd hose.. he was trying to :smiley-laughing021::smiley-laughing021: you get the idea. The radiator and engines are the same from the 2wd and the 4wd so why would there be a different hose:shocker:

Maybe but he didn't want to order it until he verified with the VIN.

[msmoorenburg]

Maybe but he didn't want to order it until he verified with the VIN.


Muddy

Pm me your info and i'll get you a straight answer with a price

[Mudderoy]

PM sent! Thanks.

Well I may not have to wait to see if that part has a spring or not. I guess I forgot about universal fit radiator hoses. The parts store guy just reminded me...

http://lh4.ggpht.com/_b0ViaGso2Ko/TGSXxR-eP1I/AAAAAAAAAY0/FGGGMvjAWkg/s640/2010-08-12%2019.52.17.jpg

http://lh6.ggpht.com/_b0ViaGso2Ko/TGSYDEoRPdI/AAAAAAAAAY4/JgeElAbnJ9g/s640/2010-08-12%2019.52.30.jpg

I'm going to try and put this on tonight, in about an hour. I can see what it does to the coolant temp tomorrow.

Then I'm going to try moving the auxiliary transmission cooler down into the bumper tomorrow night.

[Mudderoy]

It got too late and I got too sleepy to install the hose last night. I'll do it this evening.

One other thing I might try tonight depending on the outcome of the ridged hose test, adding a restrictor!

http://go.jeep-xj.info/Restrictor6.jpg

:link: (http://go.jeep-xj.info/HowtoRadiatorRestrictor.htm)

[Mudderoy]

Ok first thing I did, while I was waiting for the cooling system to cool down, was make that little washer. I drilled it out of a new cutting board, and then drilled the 1/2" hole in the center. I put it in the upper radiator hose, fit perfectlly! I started the engine. The temp was below the 100 mark, 10 minutes later it was still at this same place.

FAIL!!!

I removed the washer and I immediately got my engine coolant temp back!

This must work for a 4.0L that has the temp sensor on the back of the engine. I dunno!

Then I check the lower radiator hose. I could feel the spring and it wasn't easy to compress, so I skipped changing this.

Turns out I have what looks to be a nearly new upper and lower hose and the lower hose has the spring in it. So my memory isn't correct about moving the spring over and over since I have two lower hoses with springs.

That left me with the other thing I've been wanting to try. I wanted to move the radiator cooler over from in front of the main fan to the middle, or over the electric fan.

I wasn't very hopeful that this solution would actually be a solution so I just removed the damn thing and stuck it in my bumper! rguignard and I had discussed this on voice chat about a month ago.

Removed from here...
http://lh3.ggpht.com/_b0ViaGso2Ko/TGYzjir2Y1I/AAAAAAAAAZE/ZFdNyOg-yq8/s800/2010-08-14%2000.25.07.jpg

and moved it to here...
http://lh3.ggpht.com/_b0ViaGso2Ko/TGYzNRff7pI/AAAAAAAAAZA/tCxEv4HWhlw/s640/2010-08-14%2000.26.54.jpg

[Mudderoy]

Driving an hour at 65 mph at 9 AM Saturday morning results of changes were impressive. My coolant temp never got above about a needle's width past the 210 mark! Still not resolved but in the right direction.

After several hours of off road action, I drove up to where the water hose at the off road place is and rinsed the radiator/condenser and filled the overflow bottle.

After another few hours I was headed back home, about 3 PM. Coolant temps rose quickly to just below the first hash mark past the 210 hash. This is the same place the coolant temp was before moving the transmission cooler. Air flow does NOT seem to be an issue. At least not from the standpoint that highway speeds aren't enough to cool things. I think I'm going to have to move up to an electric fan that will move MORE air through the cooling surfaces than driving down the freeway at 65 mph does.

After a trip to msmoorenburg's shop and seeing/feeling the air from a Taurus electric fan, I think I must have one of my very own.

[Silly Willy]

I was having a similar problem, I just cut some holes in my hood, and put some covers on it. It looks decent, but now when I am going down the freeway all the hot air rises out the hood, and the engine never waivers from the 210 mark. even with me going full throttle up a canyon in 90 ish degree weather.

http://www.ksl.com/emedia/its/slc/1475/147595/14759549.jpg?filter=ksl/gallery3

O yeah I picked the covers up at Autozone for I think $5-$10 like you I was considering an electric fan... also I have a 160? ish thermostat, if that helps.

[Mudderoy]

I was having a similar problem, I just cut some holes in my hood, and put some covers on it. It looks decent, but now when I am going down the freeway all the hot air rises out the hood, and the engine never waivers from the 210 mark. even with me going full throttle up a canyon in 90 ish degree weather.

http://www.ksl.com/emedia/its/slc/1475/147595/14759549.jpg?filter=ksl/gallery3

O yeah I picked the covers up at Autozone for I think $5-$10 like you I was considering an electric fan... also I have a 160? ish thermostat, if that helps.

Thanks. I've tried everything but massive amounts of air being pulled through the radiator. The last thing was a cowl induction scoop with a huge center section of my hood cut out. It's better, but only at 45 mph and slower. A lower thermostat only keeps the coolant from heating up quickly. If you cannot cool it faster than it heats up a 0 degree thermostat isn't going to make any difference. In fact a thermostat lower than 195 can be argued that you are hurting things simply because the ECU "may" never get to the temp that it expects to see so your gas mileage suffers.

I have too much heat for my cooling system, and I suspect it is due to the rpm's that I run at highway speeds. 35" tires would probably fix the issue, or a bad a$$ electric fan or two. It's possible I have a head gasket leak, but I doubt it.

[Mudderoy]

Well it dawned on me today, I'm not very bright, that I now have a manual bypass switch installed for my electric fan. Although I wasn't on the freeway I was able to get up to 60/65 mph for an extended period. I know what the coolant temp normally reads on that stretch of the road.

So I turned off the A/C. Pressed pause on the MP3 player and hit the efan bypass switch. I heard it come on, even though the indicator light was hard to see on the switch, I could hear it running.

Almost imminently the coolant temp started dropping. I drove I coasted stopped, drove coasted stopped, and when able I did heavy acceleration. Anything with high RPMs heats up the coolant pretty fast. It kept dropping until it was about 1/2 a needle's width on the left side of the 210 hash mark.

I drove the next 5 miles or so home with the A/C off and efan on. It didn't budge from the 210-ish whether I was going 0 or 65 mph. I knew from past tests that on the freeway the coolant temp runs cooler with the a/c off but it still ran hot. That was due the efan not being on, and when it would creep up to the temp where the efan would come on it would never drop to 210 again.

This was the first time in many years that I had seen the coolant temp drop to this "magic" spot!

So I may modify my plans. I was going to the junk yard to get a 4500 CFM Taurus fan (which I'm still going to do) to try and fix this running hot issue, but now I'm considering changing out the electric fan first.

I need to search but perhaps one of you already know. What is the CFM for the stock electric fan? I have the curvy blades which is supposed to be a better air mover.

I may be on the threshold of solving this problem. :patriot:

[Mudderoy]

Well that was pretty cool.

I did a search on google for "jeep oem electric fan cfm rating" and I found the answer on the first item in the search list that google returned.

:link: (http://www.xjtalk.com/showthread.php?t=3199)

I was amazed to find out that the answer was from a jeep xj website called xjtalk! :patriot:

530 CFM is the e-fan rating. That sucks!

[valleyrayxj]

hey there i just got into the xj scene with an 89 , was overheating , ended up replacing waterpump, fan clutch , senser, thermostat all hoses , had head reserfaced,new radiator and coolant tank , everything in cooling system , took it to tahoe sucker still overheated ! Now im changing to open system with triple fan system ,its like 500 dollars but i just want this overheating thing to be gone ! You can get a laser thermometer and run it up n down raditor as well left to right to make sure it not partly plug all i can say

[Silly Willy]

Reading that link I remembered I installed a 3 Core Radiater a couple years back. It defanetly helped the temp. Thats not by chance something you have tried is it?

[Mudderoy]

hey there i just got into the xj scene with an 89 , was overheating , ended up replacing waterpump, fan clutch , senser, thermostat all hoses , had head reserfaced,new radiator and coolant tank , everything in cooling system , took it to tahoe sucker still overheated ! Now im changing to open system with triple fan system ,its like 500 dollars but i just want this overheating thing to be gone ! You can get a laser thermometer and run it up n down raditor as well left to right to make sure it not partly plug all i can say

lol yeah the cherokee's cooling system is the weak point of the design. My radiator is about 2 years old, 3 core all metal. Recently had a minor leak fixed and they tested the flow, it was very good.

I'm about to replace the factory efan and then the mechanical. If that doesn't work I may be going to liquid nitrogen.

[4.3LXJ]

hey there i just got into the xj scene with an 89 , was overheating , ended up replacing waterpump, fan clutch , senser, thermostat all hoses , had head reserfaced,new radiator and coolant tank , everything in cooling system , took it to tahoe sucker still overheated ! Now im changing to open system with triple fan system ,its like 500 dollars but i just want this overheating thing to be gone ! You can get a laser thermometer and run it up n down raditor as well left to right to make sure it not partly plug all i can say

Vallley Ray. You went to Tahoe, like up 80 or 50? Does that mean you are a California boy?

[Mudderoy]

Based on my experiment results, I've ordered a Flex-a-lite 112. I will use this 1,050 CFM fan to replace the factory electric fan rated at 530 CFM. This will almost double the maximum CFM.

I'm still planning on going to the junk yard this Saturday and pick up a Taurus electric fan.

[4.3LXJ]

Muddy

When you wire that up, I will pass something on I learned the hard way. I have dual fans that pull some amps because they pull 2000 cfm apiece. I had 50 amp relays with premade plugs that had the same size wire as the fans. I cooked two sets of them, one on the trail and lost one fan so I ran warm going up hill. I went to an auto electric place and got some rated for 50 amps. Haven't had any trouble with these yet. That Taurus fan is going to pull some amps.

[Mudderoy]

Muddy

When you wire that up, I will pass something on I learned the hard way. I have dual fans that pull some amps because they pull 2000 cfm apiece. I had 50 amp relays with premade plugs that had the same size wire as the fans. I cooked two sets of them, one on the trail and lost one fan so I ran warm going up hill. I went to an auto electric place and got some rated for 50 amps. Haven't had any trouble with these yet. That Taurus fan is going to pull some amps.

Yeah thanks for the warning. I was reading on Go Jeep about it pulling 85 amps on startup (4500 CFM) and 33 amps constant.

The electric fan I just ordered is rated at 10 amps, which is with in an amp (I think) of the stock electric fan. I'll have to double check it. My plan is to sit on the Taurus fan until I get all the parts, wire etc... I need. If the 1050 CFM fan takes care of the problem, I may sit on it a good while. :rotfl2:

[Mudderoy]

Well pick-n-pull had no love for the boys that went for the Taurus SHO 3.8L fans. We found 4 but testing them something was wrong with each.

So I came home and ordered one from ebay. :smiley-laughing021:

http://i15.ebayimg.com/08/i/001/20/47/8360_35.JPG

$65 shipped.

[4.3LXJ]

Gosh Muddy, I have one of those too sitting around

[Mudderoy]

Gosh Muddy, I have one of those too sitting around

I'm surprised you didn't pull it into service.

[4.3LXJ]

If I had a different shaped radiator I would have.

[Mudderoy]

Amazon finally shipped the electric 1050 CFM fan! Woohoo!

[Mudderoy]

Electric fan should arrive this Thursday. I think I'm going to use the OEM fan housing to mount the new fan to. I'll be able to tell more once I have the new fan.

BTW I have a brand new $110 replacement electric fan from O'Reily's. Brand new as in never used. I took the old one back because the electric plug messed up. Turns out I'm not going to use it since I'm replacing it with this aftermarket electric.

[Mudderoy]

Flex-a-lite 112 came in. It says 1107 CFM on the box. It's a small thin fan. Interestingly it is rated at nearly 10 amps, and from what I'm reading the OEM fan runs 13.5 amps. I should be able to use the stock electrical connection then!

[Silly Willy]

Flex-a-lite 112 came in. It says 1107 CFM on the box. It's a small thin fan. Interestingly it is rated at nearly 10 amps, and from what I'm reading the OEM fan runs 13.5 amps. I should be able to use the stock electrical connection then!

Thats awesome, keep us posted.

[Mudderoy]

So I was looking at the new fan and the new OEM fan that I have.

The best I can figure is I need to build a bracket that the new fan fits to then that bracket (or brackets) will fit to the stock mounting points.

I was thinking of a hard plastic, like a cutting board. Cheap, tough and easy to cut with a dremel tool. I don't know how much heat they can take though.

Anyone have any idea how much heat they can withstand?

[4.3LXJ]

It is a crap shoot with plastic. There is so many formulations for plastic it would be impossible for me to guess. If I was doing it, I would use aluminum and pop rivets to hold it together. That is how I built the first one I ever made. Still have it. It was very strong.

[Silly Willy]

It is a crap shoot with plastic. There is so many formulations for plastic it would be impossible for me to guess. If I was doing it, I would use aluminum and pop rivets to hold it together. That is how I built the first one I ever made. Still have it. It was very strong.

I have to agree. it would probably be the cheapest, and most effective way to do it

[Mudderoy]

I made a simple, crude, but functional adapter to mount the flex-a-lite fan in the stock electric fan location.

Since the current draw is actually slightly less than the OEM fan I just used the factory wiring. Works fine, but it doesn't seem to cool as well as the OEM fan. I am sure this is largely due to the 1/2 inch gap on the sides of the fan. Also the OEM fan has a built in shroud, of sorts, that allows the air to be pulled from a greater surface area.

This was good for a test. I'll probably go back to the OEM fan until I can fabricate a shroud for the electric fan to mount to. I have a spare 2 core all metal radiator that I can use as well as a spare OEM electric fan.

The Taurus fan should be in tomorrow. It should be much easier to fit since it has it's own shroud. If it will fit between the radiator and the engine. The main issue with it will be electrical. I have to be concerned about the 85 amp start up of the 4500 CFM setting. The 2500 CFM setting should be able to be handled with a relay and fuse I already have.

I'm not sure if I want to have the 2500 CFM come with the ignition, and have the 4500 CFM selectable from a switch, or just have both controlled with temp sensors. Say 180 for the 2500 and 220 for the 4500 CFM. Adjustable temp sensors would work out best as I could adjust them to keep the coolant temp close to the 210 mark.

[Mudderoy]

4.3LXJ how did you go about making your aluminum box? I'm thinking of cardboard to get the shape of the pieces, and folds, then cut and bend the metal to match each piece. What thickness aluminum did you use? :popcorn:

[Mudderoy]

Well I found this little jewel today!

http://xjtalk.com/images/special/2sp.jpg

:link: (http://dccontrol.com/fancontrol.htm)

It controls 2 speed electric fans. Specifically mentions the Ford Taurus 3.8L fan. Low speed at 180 +/- 30 degrees and high speed 10 degrees above the low speed setting.

[4.3LXJ]

4.3LXJ how did you go about making your aluminum box? I'm thinking of cardboard to get the shape of the pieces, and folds, then cut and bend the metal to match each piece. What thickness aluminum did you use? :popcorn:

I used sheet and angle aluminum from the building supply. 16ga on the sheet I think, 18ga works well also. Whenever you need a 90° bend you use a piece of angle and pop rivet to it. All my bends were 90° of course s I ended up with a shallow box

[Mudderoy]

I used sheet and angle aluminum from the building supply. 16ga on the sheet I think, 18ga works well also. Whenever you need a 90° bend you use a piece of angle and pop rivet to it. All my bends were 90° of course s I ended up with a shallow box

Gotcha! Thanks.

[Mudderoy]

A very good article...

:link: (http://www.arrowheadradiator.com/14_rules_for_improving_engine_cooling_system_capab ility_in_high-performance_automobiles.htm)

[4.3LXJ]

Read that, very imteresting

[Silly Willy]

Lots to read, but very impressive.

[cantab27]

well I'm on this now ,, wheeling today and she boiled on me twice ,, this was on a tight trail in trees with no breeze and hot as hell ,parked her up and water was boiling in over flow bottle ,, sat for half hour got radiator cap off but was full ... got on river bed in open spaces in and out of river and she stayed cool for rest of trip .....but water in rad is dirty brown color .... should i start with a flush and see if this happens again ???
and can i post this question in here tony or else where ...lol

[Mudderoy]

well I'm on this now ,, wheeling today and she boiled on me twice ,, this was on a tight trail in trees with no breeze and hot as hell ,parked her up and water was boiling in over flow bottle ,, sat for half hour got radiator cap off but was full ... got on river bed in open spaces in and out of river and she stayed cool for rest of trip .....but water in rad is dirty brown color .... should i start with a flush and see if this happens again ???
and can i post this question in here tony or else where ...lol

I would get all the gunk out of it. Mine was like that when it was about 2 years old. I cleaned everything really good and now she stays a nice clear green.

Mine stays nice and cool and low speeds now since all my modifications.

Here is fine. :thumbsup:

[cantab27]

cheers mate , first time it has done this ,, but was hot as on the trail stuck behind other rigs ,,, will give it a flush then ...

[Mudderoy]

I was just reading through this thread and I see where a reader may think this running hot problem has been resolved. It hasn't. I still get close to the first hash mark past 210 on the freeway.

I am considering an aluminum radiator, or a 2 core all metal.

[Mudderoy]

I found this old post on NAXJA... 05-09-2008

Summer temps - XJ Starting to run hot.

Ok I drove home today and didn't exceed 72 mph. Temp was better. When I got home I grabbed the IR gun and started getting some temps.

Just for grins the hood was 175 degrees, as was the inside of the hood.

The thermostat case was 210.5

http://muckleroy.com/images/jeep_temp1.jpg

The Jeep temp gauge read over 210 degrees.

http://muckleroy.com/images/jeep_temp2.jpg

The over flow bottle level was just below the FULL line.

Yesterday the needle was much closer to that first hash mark after the 210.

The outside air temp today is 91 degrees, so it is hotter outside than this time yesterday.

UPDATE: Ok well screw it! I just ordered a 3 row radiator from radiatorbarn.com (gotta love that name).

http://muckleroy.com/images/jeep_temp3.jpg

I called them and asked them about the size of the tubes. They are the same size as the two row (core), just one more row. Helpful, professional, now I'll have to wait and see how the rest goes.

[Mudderoy]

Then this post after the installation of the CFS radiator... 05-18-2008

I put the 3 core in today. Took it out the highway and put the cruise on 80 mph and drove out about 5 miles.

Exited and pulled over to look for leaks. Clean and the radiator had that "new hot paint" smell! lol

Ran 210 the entire 5 miles. After I pulled over to check for leaks the needle moved slightly above 210, technically the needle was still on 210 hash mark.

I got back on the highway going the opposite way. It took a couple of miles for it to drop back to 210.

I ran the A/C the entire time. I'll double check the coolant level tomorrow as I just topped off the new radiator before warming it up and then doing the test drive.

This coming week will be the real test, as we are expecting 90's in the afternoon, and that is always the time that I have issues. I am thinking about taking the old radiator to a shop to have them test and fix any leaks. It would be nice to have a spare.

[Mudderoy]

Then this on 06-16-2008

Update:

As stated before, thermostat, thermostat housing changed.
3 core radiator installed
upper and lower radiator hoses replaced
heater hoses replaced
water pump replaced

I didn't have any coolant available so I filled it up with water.

Replaced diff gear with 4:56 gears.

Coming home on I-10 at 3200 rpm for 5 minutes. Temp neared the first hash mark after the 210. I exited I-10 and rpms dropped to 2200 or less. The gauge stayed there for a couple of minutes and started coming back down to 210.

By the time I got home, another couple of minutes it was close to the 210 hash mark.

No leaks, no smells of coolant. Reading back in the responses it sounds like a water pump issue, or clogged something. With a new radiator I'm not sure what could be clogged unless it was in the block.

The mechinical fan clutch was replaced about two years ago.

I'll check the coolant level, and I'll probably drain off some of the water and replace it with the antifreeze I bought to see if that helps.

It's running fine, and it didn't over heat, I am just confussed as to why it would get so high above 210. I understand it is generating more heat the faster I run the engine, but still....

[Mudderoy]

Update!

Due to information received on xjtalk from it's members I have ordered, received, installed and I am currently testing a new Performance Radiator 1 row aluminum core with plastic tanks radiator.

Initial results show that the single row aluminum radiator is far out performing the 3 row cooper/brass.

A 20.6 mile round trip test last night at 70 mph resulted in a coolant temp not quite 210 degrees. This was a night time test and not the harshest test. I will be driving home via the multiple freeways (and a toll road) today after work to give it a true test. High speed, high heat, and high humidity.

You can read more about the radiator here ==> :link: (http://www.xjtalk.com/showthread.php?t=7847)