Oil Dipstick Tube [Archive] - xjtalk

Melissa

01-04-2010, 10:40 PM

Ok here goes.

Awhile back I was getting blowby from my dipstick tube, I replaced all the vacuum hoses going to and from my valve cover, cleaned the valve cover, cleaned all the pvc parts and the blowby stopped. Well it came back yesterday, but I am getting very little blowby compared to before.

A friend of mine said he read somewhere that in the early 90's year of jeep they put the wrong dipstick tube in causing you to overfill your oil by one quart, in return causing blowby from the dipstick tube and over heating problems. Now, I searched all over the internet for where he found this, but I have come up with nothing, nada, zip, zero. Has anyone heard this before??

What else can I do?? What is causing this??

:smiley-scared002::smiley-scared002::smiley-scared002:

TheWeiss

01-06-2010, 12:34 PM

To be honest I don't even know what "Blow By" is.... school me?????

BlueXJ

01-06-2010, 12:43 PM

Melissa

01-06-2010, 01:28 PM

Yup, thanks Blue.
like I said it's not much, I'm only seeing a few drops of oil on the vacuum line right behind the dipstick tube and none in the airbaox, but as I have already sunk a bunch of money into this donor motor, a few drops and the fact that I am again getting the blow by, worries me.

TheWeiss

01-07-2010, 08:25 AM

Thanks for the run down.... I'm still working on the lingo... and its a work in progress.

Mudderoy

01-07-2010, 08:44 AM

Blowby is the result of combustion chamber pressure seeping past worn rings into the crankcase. That increased pressure shows up as oil in the airbox from the increased flow through the vacuum lines and also by oil being "blown" out of the oil dipstick tube.
HTH

Seems like I remember something about a block PVC valve also causing this problem? I don't have one in my year XJ but I thought Mel does (her Jeep). Maybe I'm remembering wrong about the blocked PVC...

Melissa

01-07-2010, 04:09 PM

Seems like I remember something about a block PVC valve also causing this problem? I don't have one in my year XJ but I thought Mel does (her Jeep). Maybe I'm remembering wrong about the blocked PVC...

Yup, that was my problem the first time around, well not actually the pvc valve (I cleaned it anyways) it was the pvc line running from the valve cover, it was all kinked.

Mudderoy

01-07-2010, 04:12 PM

Yup, that was my problem the first time around, well not actually the pvc valve (I cleaned it anyways) it was the pvc line running from the valve cover, it was all kinked.

So that's clear this time?

xj4life2

01-07-2010, 04:41 PM

I'm sure your aware of this but just in case.... If you follow the line from the pcv oriface in the back of the valve cover it runs to the intake. Pull the vac line off and by hand useing a 1/8 drill bit clean out that nipple.That being clogged is actually the biggest cause for oil in the air box syndrome. As for the dip stick thing I have never heard that and its not listed in any TSB or recall on the XJ.

BlueXJ

01-07-2010, 08:36 PM

Well the dipstick thing is just from years of experience and a smattering of common sense. pressure will alway seek relief and the o-ring on the upper end of the dipstick holds little resistance.

Melissa

01-08-2010, 02:18 AM

So that's clear this time?

Yes, I have checked, checked and rechecked, but its all clear.

I'm sure your aware of this but just in case.... If you follow the line from the pcv oriface in the back of the valve cover it runs to the intake. Pull the vac line off and by hand useing a 1/8 drill bit clean out that nipple.That being clogged is actually the biggest cause for oil in the air box syndrome. As for the dip stick thing I have never heard that and its not listed in any TSB or recall on the XJ.

Thanks payless, I have done that.

None of this makes any sense at all :sad0147:. I am trying test, according to my dipstick tube, I am one quart low on oil right now, I am going to run it like this for a few days to see if I get any more blowby, then filler back up and see what happens. I know this is not solving my problem, but I want to see if the dipstick theory has any merit at all.

Mudderoy

01-08-2010, 09:03 AM

Yes, I have checked, checked and rechecked, but its all clear.

Thanks payless, I have done that.

None of this makes any sense at all :sad0147:. I am trying test, according to my dipstick tube, I am one quart low on oil right now, I am going to run it like this for a few days to see if I get any more blowby, then filler back up and see what happens. I know this is not solving my problem, but I want to see if the dipstick theory has any merit at all.

I can't remember, did you do a compression test? Really easy. Just pull the relay for the fuel pump. Remove a spark plug. Screw in the gauge where the spark plug was and stand clear of the moving bits and turn the engine over. Read PSI. They should all be about the same. 135 psi comes to mind, but I'd have to look it up. I think the gauge is about $35.

Put that spark plug back and move to the next one.

I haven't done a compression test in years, so read up on how to do it before hand.

BlueXJ

01-08-2010, 09:20 AM

Remove all the sparkplugs to make it easier for the engine to spin up.

cheap jeep

01-08-2010, 05:23 PM

When you have your oil changed ,see how many qts. they put in(mine holds 6 with filter) and then see where it reads on the dipstick. Did this problem happen before it got really cold? I was wondering about possible condensation. When I buy a used vehicle,I remove the oil fill cap with the engine idling,rev it up for a few seconds, and watch how much smoke comes out Watch for moving parts!Be careful.

TheWeiss

01-09-2010, 10:01 PM

What does the smoke mean? Moisture in the oil?

cheap jeep

01-10-2010, 09:01 AM

When you hit the throttle briefly and a lot of smoke comes out it is usually an indication of blow-by.If you remove the oil fill cap and it looks like a milkshake that has a melted,this is caused by moisture in the air in really cold weather.It could also could come out the vent tubes in small amounts,this is normal and I've seen it for years on good engines.This will go away when it warms up again.

Melissa

01-14-2010, 04:33 AM

Thanks guys, sorry I have been absent for a few days, but I'll try both the compression test and taking the oil cap off. I let you all know what happens

PS.............. might be a few more days before I can get to my jeep, my Diesel has a bigger oil problem that needs to get found and fixed ASAP, really need my Diesel!!!