I recently purchased my 2000 XJ with 96000 orig. miles. It didn't leak when I purchased it. After 1K miles I saw a single drip on the ground and one on the bell housing of the trans (auto). Took to local mechanic. Had the rear main seal replaced as well as pan gasket. After that, it leaked everywhere. All around the pan, but impossible to tell if the rear main seal was leaking. Took it to the dealership, in hopes they would do a more thorough job, and if not correct, they had the resources to work it out.

They said the pan was warped and the RMS did not appear to be leaking as they saw no oil on the trans where the seal is located. Had the pan replaced with new mopar and another new gasket. When complete, they indicated they ran it and had no leaking. I drive it 15 miles and it is still leaking. The leak is now only down the bell housing and it drips 3-5 times after I turn it off. It is also blowing back across the trans pan, but the trans pan seal seems dry. I have another appt with them to correct this issue, and we are adding dye this time.

What are we missing? It is very frustrating when the supposed experts are struggling to make this work out. And, Why did the lead mechanic for JEEP tell me "these things leak sometimes"? I disagree with that position. I don't believe they leaked from the factory.

Any others have this persistent problem? Is there an "aha" moment of correction? Or, is it likely the seal was installed incorrectly, and they will need to do that all over again?

Thank you,
Darryl

 

Unless you have absolutely proven it is not the oil filter adaptor o-rings leaking, it should be considered highly suspect.

Clean under the adaptor housing with degreaser & white cloth till it is spotless...idle the engine for 5mins..there should be NOT ONE DROP of oil in your newly cleaned area

O-ring kit cost $4

 

Valve cover, Oil filter adapter orings are two big ones.

The last XJ I bought leaked from everywhere including the the oil galley (passenger side) of the head (seeps a good bit of oil) and timing cover gasket and crank seal. At this point I've fixed all of them but the oil galley leak which leaks enough to be annoying but not enough to cause a significant drop in oil. I also found out the previous owner(s) put the wrong front CCV elbow in which I think may have been causing an over pressure issue in the crankcase which may have at least contributed to the cause of these oil leaks.

 

valve cover gasket? that was it on my 92 4-0

 

 

My oil filter adapter leaks although it's not too bad. It seems that the oil that leaks from there travels back to the rear of the engine along the lip at the engine/oil pan junction. So to answer your question. Yes it can travel down the bell housing.

 

CRUISER'S MOSTLY RENIX TIPS

REAR MAIN SEAL DIAGNOSIS

OCTOBER 31, 2015 SALAD 2 COMMENTS EDIT

I’d be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn’t own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don’t jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons:

First off, the engine sits nose-up and any oil will run back to the RMS area.

Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber’s adage apply here: “Crap flows downhill”.

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first. A little tip here. Rather than use a dizzy gasket, use an o ring instead. NAPA #727-2024. Tips 12 and 13 will help you get your distributor back in place correctly.

 

Boom and there it is
One day I'll be able to paste that post in before Cruiser gets to the thread! LOL...

(he's right, of course)

 

Come on Quickdraw!!!!

 

It must be it took 4 hours to cross the pond! LOL!

 

ok, So I did some poking around and it does not look like it is leaking from the oil pan, RMS, valve cover, or the oil filter adapter. However, there is leaking from the starter where the motor meets the housing. It is leaking down and back onto the bell housing. Anyone have this issue? Is this a thing? And can I now assume its Trans oil?

Thank you,


Darryl

Starter and bell housing leak

 

Reach your hand to the back of the valve cover. I bet the rear bolts are loose.

 

You think the valve cover may be loose closest to the firewall? Ill check it tomorrow. I found it weird to have oil coming from the starter. Thank you for the idea.

Darryl

 

Also, I cleaned it really well in hopes to get a true idea from where the oil is originating. I took it around my development, but there was not oil present. Elusive for sure.

 

You'll find it.