Leaking Oil

'92 4.0 165,000. I have been leaking oil for about three months. The entire under carriage was covered. I thought for sure that the rear main bearing seal was shot. Not the case at all. There is a large O ring that goes to the oil filter assembly. It was hard as rock! Cost $9.00 and the leak stopped. My suggestion for anyone with a leak...check the oil filter mount.

do you just remove the threaded part?

On mine I could see it leaking when the engine was first started but it would stop when the motor warmed up. This oil filter mounting assembly bolts to the motor with a t-60 torx fastener and is 2-3 inches across from the frame. A 1/2 inch drive t-60 socket fits into the fastener but there is no room left for the ratchet. After searching for all different types of torx wrenches and not finding any that would work, I ground down opposite sides of my socket to make a 13/16 open end wrench fit on it. It was very hard to break loose. Be carefull not to let the torx bit come out of line and strip the head.
BTW- the o'ring seal pkg for my 94 was $3.50 from my Jeep dealer and contained all 3 of the o'rings used in the assembly. Part #4720363

I beleive these types of threads are exactly what is needed. Thank you for the advice. Personal experience in trouble-shooting is often far better than asking a mechanic in a dealer's shop. That leads me to also advise those with hard-to-find oil leaks on the XJs to have someone at a shop drain about a quart or so of engine oil out and theres this oil dye you can pour in that turns the oil flourescent green. With the lights turned low and a flourescent light shined on the underside of the engine you will see exactly where the leak is streaming from. The green oil shines in the light like a Jimi Hendriks poster under a blacklight in your bedroom when you were a kid.
I had an impossible to locate oil leak on my '94 Sport years ago and after spending time and money replacing every engine gasket including the main seal and going back and forth to the shop six times, I had this done. Immediately they located a tiny trickle coming from a $1.83 O-ring
around the distributor shaft. You might want to drain and refill the crankcase with fresh oil afterwords because the next time you check your oil you might freak thinking anti-freeze got into it because the oil looks just like fresh Prestone with the dye in it. Doesn't hurt nothing, but it causes a cold-sweat panic until you remember what you did!
tb

I had to change the pass side motor mount and had to remove the oil filter adapter in order to remove the engine mount bolt. I found that all of the o rings were hard and one even split. I spent more time searching auto parts stores to buy those dang o rings than it took to replace them.

After changing the rear main seal, oil pan gasket, valve cover gasket, oil filter adapter o rings, "PCV" breather grommet and a few other seals, my '88 is pretty oil tight now.

I had the same problem, I thought it was the pan gasket, so I put a bunch of stop leak in there didnt help. Ended up being the bottom of the filter mount just tightened that cover and leak went away. :sly:

After changing the rear main seal, oil pan gasket, valve cover gasket, oil filter adapter o rings, "PCV" breather grommet and a few other seals, my '88 is pretty oil tight now.[/QUOTE]

I'm doing all that to my 2000 Sport tomorrow. Don't forget that seal around the distributor shaft. That caused me a major headache when my '94 leaked. I changed everything you mentioned, but it still leaked. It had all the mechanics at the repair shop scratching their heads until they found that little .43 seal.
tb