I'm noticing a small oil leak after the engine runs. My XJ is a 95, and it currently has 73k miles on it. I purchased it last July with 64k, and it did not leak fluids, until the winter time roughly. I've been changing the oil every 3-5k miles roughly. I degreased around the oil filter adapter, and I do not see any leaks from above. From the underside, it looks like it may be leaking VERY slightly. The drip spot on the ground is probably about the size of one or two half dollar coins.

I'm attaching a few photos. I took them at night time, so I apologize if it's hard to spot the leaks. I can retake photos if necessary.

Does it look like this leak is coming from the oil adapter and/or the RMS (rear main seal)? I felt around the rear of the valve cover, and it is dry to the touch.

 

I would go with the oil filter adapter o-ring. It is a common place for XJs to leak and the oil can work it's way down the block and drip out near the rear main seal and trick you into thinking the leak is there.

 

Guess I will replace those o-rings first. If not I'll take a look into the valve gaskets before the RMS

 

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, people on Jeep forums who can’t see your Jeep from where they’re at, 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. "$hit 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.

Revised 02-26-2013

 

X2.......When I bought mine I was told the RMS was leaking, it was not all it was in my case was the oil filter adapter O-rings.

 

I just degreased the entire engine bay, as well as underneath the engine. After driving two miles, the picture below shows how much oil drips. From what I could see, the block and around the oil filter looks dry. No visible oil on the block or near the oil filter. The drip is right below where the RMS is located. Also prior to the degrease, it was not wet behind the valve cover where it is known to be a leaking area.

What do y'all think?

 

I just went back and rechecked everything again.. part of me think it is actually the o-ring on the oil adapter. Upon further inspection, it looks like the leak is starting from up high, but on the other hand, it looks like it could be leaking on around the pan gasket.

 

I don't think you'll be able to fix the oil leak until you determine it's origin.

 

YUP! Well stated and true.

 

I ignore my oil leaks. I just add a quart now and again

 

A lot of overthinking going on here, OP.

Replace O rings. Check for leaks. Fixed? Great and was cheap.

Still leaks? No big deal, now onto the next culprit.

 

What causes oil to flow into the distributor and drip out of the drain hole?
Yes I am absolutely certain this is what it it, I have cleaned and checked, replaced everything IE RMS. pan gasket, oil psi sender, adapter O rings, valve cover gasket, distributor gasket. I can watch it drip out of the distributor....

 

A crappy distributor.

 

I had suspicions on that. Can they be rebuilt/bushed or is it dead, put another one in? I thought it had a lot of slop in the shaft, I pulled it apart, cleaned and checked for galling or any other bad signs, the only thing I found was a loose fitting shaft.




Thanks Cruiser

 

Get a new or rebuilt one.