Leakn
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Seasoned Member
Joined: Jan 2009
Posts: 261
Likes: 0
From: Central NJ
Year: 2000
Model: Cherokee
Engine: 4.0
I've had an oil leak on my jeep for a while and i was told it is probably the main seal. After i drove it and parked it, I took a look under to see where the drops of oil are coming from. They drop from those two areas. By the picture can you tell what it could possibly be leaking from?
Seasoned Member
Joined: Dec 2011
Posts: 319
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From: High Desert, CA
Year: 1987
Model: Cherokee
Engine: I6
The rear of the valve cover can cause a leak that appears to me the rear main. Most likely it is the main but you should confirm it.
Here is a write up:
http://jeep-xj.info/HowtoRearMain.htm
Here is a write up:
http://jeep-xj.info/HowtoRearMain.htm
CF Veteran
Joined: Oct 2011
Posts: 4,440
Likes: 3
From: Seal Beach, CA
Year: 1996
Model: Cherokee
Engine: 4.0 HO Straight Six
Write-up: http://jeep-xj.info/HowtoRearMain.htm
Before jumping to the conclusion that it's the rear main seal, you first want to verify that it's not a leak at the valve cover (at the back of it) or the oil filter adaptor. In both cases, the oil drips down to the rear main seal area, making it look like a rear main seal leak. My advice would be to degrease the engine (there are many threads on how to do it), drive it around for a couple days and check again to see where it's coming from for sure. The rear main seal is a VERY common area for it to leak though, so it may very well be there. But you should verify for sure because both the oil filter adaptor o-rings and valve cover gasket are much easier to replace than a rear main seal.
Edit: ^^ he beat me too it
Before jumping to the conclusion that it's the rear main seal, you first want to verify that it's not a leak at the valve cover (at the back of it) or the oil filter adaptor. In both cases, the oil drips down to the rear main seal area, making it look like a rear main seal leak. My advice would be to degrease the engine (there are many threads on how to do it), drive it around for a couple days and check again to see where it's coming from for sure. The rear main seal is a VERY common area for it to leak though, so it may very well be there. But you should verify for sure because both the oil filter adaptor o-rings and valve cover gasket are much easier to replace than a rear main seal.
Edit: ^^ he beat me too it
Thread Starter
Seasoned Member
Joined: Jan 2009
Posts: 261
Likes: 0
From: Central NJ
Year: 2000
Model: Cherokee
Engine: 4.0
ha wow that was fast guys. ok yea i was thinking it was the rear main seal. ill degrease it this weekend and check where it leaks from. thanks for all the help
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I have the same thing. I stop the truck, look under and can see the drips. The drips only continue for 15 or 20 minutes. Maybe I'll be lucky with the valve cove. Also, I can smell it which may mean the leak is up higher than the main seal.
Originally Posted by Fallen
I'm almost 100% that you have a leaking rear main seal. it drips down from between the transmission and oil pan.
CF Veteran
Joined: Oct 2011
Posts: 4,440
Likes: 3
From: Seal Beach, CA
Year: 1996
Model: Cherokee
Engine: 4.0 HO Straight Six
If you know what you're doing, I could imagine it would only take a day (or a few hours work for that matter)..... And wouldn't cost more than your adult beverage of choice, the rear main seal, and oil pan gasket themselves
When I did my 2000 cherokee freedom 4.0L I had to buy 2 rear main seal set's my bottom 1/2 was the same as the top 1/2 ( no tabs ) like seen in the repair manuals. I did need to remove lower control arms to let axal come down enough to get the pan off.
NO LEAKS
NO LEAKS CF Veteran
Joined: Jan 2011
Posts: 1,894
Likes: 4
From: Las Vegas
Year: 1999
Model: Cherokee
Engine: 4.0
Not worth trying to find the leak/s, just replace the following gaskets.
Valve cover gasket (Felpro)
Oil Filter Adapter O-rings (dealership)
Rear Main Seal (dealership)
Oil Pan gasket (Felpro)
If the above gaskets have not been replaced, i would just replace them cause eventually they will leak.
Beside the RMS and the Oil Pan gasket, the rest are a walk in the park and if you do some research, less than $100 will be you an oil free engine bay.
GL.
Valve cover gasket (Felpro)
Oil Filter Adapter O-rings (dealership)
Rear Main Seal (dealership)
Oil Pan gasket (Felpro)
If the above gaskets have not been replaced, i would just replace them cause eventually they will leak.
Beside the RMS and the Oil Pan gasket, the rest are a walk in the park and if you do some research, less than $100 will be you an oil free engine bay.
GL.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Hold on! When the oil filter adapter O rings harden, it leaks and the oil blows right back and drips there looking exactly like the RM is shot. I'd blast it good at the car wash, then watch right away!. It might be all over in just a few minutes, then you are right back to not being sure where it came from.
Also it's important that the rear CCV is sucking, (the tube gets clogged), also the front needs to be free to vent any blow-by to prevent "positive crankcase pressure".
And yea ^^. If it looks like the valve cover might be leaking you might as well fix that first.
Also it's important that the rear CCV is sucking, (the tube gets clogged), also the front needs to be free to vent any blow-by to prevent "positive crankcase pressure".
And yea ^^. If it looks like the valve cover might be leaking you might as well fix that first.
What's the trick to getting the oil pan out? I got the flywheel inspection cover off, loosened the exhaust, tried multiple ways to get it out and am now looking for advice on how to get it out. I have been following directions from AllData. My Cherokee is still stock height. 
While i've got the pan out I am also gonna do the rear main seal. I thought I would have to pull the trans like on other vehicles. glad to see the diy.

While i've got the pan out I am also gonna do the rear main seal. I thought I would have to pull the trans like on other vehicles. glad to see the diy.


