Should you reuse a water pump?

[Mudderoy]

I had a perfectly good water pump on my 4.0 a few years ago, and took it off as part of a over heat experiment.

It is a bad idea to reuse a water pump? The reason I ask is it is a FlowKooler and was about $100.

I have a replacement coming in but I thought why not try the FlowKooler again to see what difference it makes, if any. I'm really not keen on the idea of replacing a water pump twice though...

[4.3LXJ]

IIRC you didn't use that pump much. I would use it if it were me

[Charlie Foxtrot]

When I started turning a wrench in my uncle's shop 50+ years ago, we reused water pumps all the time (ie: if pulled as part of an R&R of timing chain on a V8). If we had any concerns, we would press it apart & replace the seal. If the bearing was rough, we would replace it as well. Now, the one caveat is that if it's a major PITA to change out or it's failure would take out a timing belt then I'd replace the pump with new. As none of those issues apply to your 4.0L, reuse at will, and sleep easy.

[jonb8]

The fan doesn't hang off the waterpump on a xj so the bearings never go out. The water blades will rust off first. I've reused them for years, If I install a used motor I pull the pump off check the blades and put it right back on.

[bluedragon436]

The fan doesn't hang off the waterpump on a xj so the bearings never go out. The water blades will rust off first. I've reused them for years, If I install a used motor I pull the pump off check the blades and put it right back on.

I won't say the bearings never go bad.. that's what went out on my 98's water pump (don't ask me how, I don't know).. But yeah, I know generally they don't fail other than the blades.. I'd say in your case Tony.. you didn't use it all that long, and it didn't go through any abuse.. so should be good to reuse it..

[Mudderoy]

Prior to installing the FlowKooler, which I was able to find and checked... I thought I'd run a pressure test on my cooling system.

Pumped it up to 16psi and heard a drip, drip, drip.

Coolant was slowly dripping from heater hose line running to the metal pipe that screws into the water pump.

Tightened up the hose clamp and no drip. Pressure still bled down, but about 3 or 4 times slower than before, and it was already slow.

So I still have a leak somewhere in the system or it was leaking from the pressure tester. I'm going with the latter.

I'll drive it to/from work in the morning and we'll see if that fixed it.

Normally I'll hit 230 after driving 20+ miles at 70 mph and coming to a stop at a light. Drops 3 to 5 degrees as soon as I start moving again. After about 3 miles at 40 mph or less it will drop to 215, or so.

The problem I was having was a strong smell of coolant first thing in the morning (depending on A/C being on or not) and Monday I hit 233 while still on the freeway at 70 mph.

[Mudderoy]

Hit 230 on the way in to work this morning, and that was when it was dark outside (and cooler). The leak is back, I have another problem, or there is air in the system. I'm hoping that after it cools and sucks up the overflow it won't run 230+ going home this afternoon.

I got off the freeway and it started dropping. It was 217 before I turned into the parking garage.

Gotta find the issue before summer gets here.

[Pookapotamus]

What shape is your heater core in tony? If you are smelling coolant in side that could be the problem. Have you flushed the system? I see you have A/C, what shape is the condenser up front in? Any white smoke when starting? What shape is the rad in? This might sound stupid, but did you change the belt routing at all? And another silly one, is your coolant at the right strength? What rad do you have, single core? Dual?


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[denverd1]

depends. Its not the water pump itself, its getting to it if you need to replace it. having the water pump exposed usually means you are chasing a bigger problem on an older engine and a $100 pump is a cheap serviceable part that probably makes sense to replace in the grand scheme of things.

your case? heck yea i'd use it

with your gears, I can't imagine you turning a lot or rpms on the freeway. kinda bizarre that it gets hot at speed, then cools as you sit in traffic.

[Mudderoy]

What shape is your heater core in tony? If you are smelling coolant in side that could be the problem. Have you flushed the system? I see you have A/C, what shape is the condenser up front in? Any white smoke when starting? What shape is the rad in? This might sound stupid, but did you change the belt routing at all? And another silly one, is your coolant at the right strength? What rad do you have, single core? Dual?


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Forgot to mention... I kept the A/C off this morning and no coolant smell. I was only smelling it when the air from outside was free to come in.

I'd have to check the video for the date but the heater core was changed a few years ago. Seems like 3 may be 5. Radiator is newer than that.

[Pookapotamus]

I'll check to see what I am running today on my drive to work tony.


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[Pookapotamus]

Well tony, I typically sit about 195 - 200.




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[Mudderoy]

Wish mine did. If the outside air temp is much above 80 I'll hit 220 after I get off the freeway.

As air temps get into the 90's it will hit 230 stopped at a light and drop when I get moving again. Typically it will get down to 215 after the 3 miles from the freeway to the house and the 5 lights.

I think my biggest issues are the area I live is is hot with high humidity, and 4.56 gears on 33's. I run about 2700 rpm on the freeway at 70 mph.


Well tony, I typically sit about 195 - 200.




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[Mudderoy]

Drove the XJ to work Wednesday. Hit 230 near the office which is really strange for it to do that in the morning, dark, usually cool air temps.

Coming home hit 230 on the freeway, got up to 235 off the freeway and actually died as I was taking a turn on to the road leading to the house. Made it about a mile before it started running rough, so had to pull over.

Turned it off and the gauge and the external gauge went to 260.

I was there about 30 minutes waiting for it to cool off. Once it got down to 230 I started it up and the fans and water pump turning brought it down to 215 pretty quick.

Started the drive home and it started heating up quickly. I was at 225 by the time I got home.

Ran the hose on the radiator to drop temps down to below 210. Filled up the over flow bottle. Then let it sit several hours.

Checked radiator and it needed some water. Checked the overflow bottle and it was EMPTY!

Got out there Sunday and first things first I put the coolant system tester on it.
10150

After I got it up to 16 psi I noticed this...

10151

That's the top of the water pump. I had noticed some bubbling water after pulling over during the overheat but just assumed it was some coolant coming from a heater hose, but this was actually coming out from behind the water pump!

The 16 psi drops almost immediately but goes down very slowly.

I broke out the socket and ratchet to check the bolts on the water pump.

I was able to tighten them all, and not really trying very hard. Wiped away the coolant from the top of the water pump.

I pumped the tester back up to 16 psi and it dropped slower, but still dropped. But now no leaking of coolant on top of the pump.

It held the 16 psi for probably 5 minutes before I noticed a drop. Of course it's always possible that the pressure tester has a leak.

I gave Matt a call to get his advice in if I should test it after tightening the bolts or go ahead and replace the pump. Like me he was concerned that the gasket may had a problem now so just change the pump.

He doesn't like the FlowKooler so recommended using the new OEM style pump.

I got the old pump off pretty quick and found...

10152 10153

Well that was unexpected! :rolleye0012:

The old water pump appeared to be fine. Bearing felt solid and had some resistance to turning, not as much as the new one but this one had 20k miles on it(?). I didn't see any signs of coolant discoloration indicating a leak on it, but then again the coolant was really clean so it may not have caused a sign.

After getting everything buttoned back up, new pump installed, card removed, I ran the engine probably for a good 30 minutes with the rad cap off watching the coolant temp waiting for the thermostat to open.

It finally did after belching out some coolant. Put more water in and made sure the overflow was full.

Ran it a while longer, never got above 200(ish). It was getting close to 10pm and I needed to eat and get to bed.

Probably should have replaced the thermostat while I was at it, but really I don't recall ever having one go bad.

I haven't found a smoking gun as to the cause of the over heat so I'm a bit nervous if I have found the solution. Can't drive it to work not knowing.

Plans are to test it after to work.

[Pookapotamus]

It's a start tony! Pay special attention to the thermostat, I have found that some have a ridge around the circumference and they don't fit with all the different head castings, caused a weep in mine that took a while to diagnose.


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[abebehrmann]

I got the old pump off pretty quick and found...

10152 10153

Well that was unexpected! :rolleye0012:



Found the same damn thing in my AC evaporator when I changed it out a couple weekends ago! That show really does get around! :patriot::patriot::patriot: