Major oil leak, any ideas?

[dave92cherokee]

Well this is one that has me scratching my head. My 92 sport 4.0 has been very good to me but yesterday developed from a very slight oil leak to developing a 12" puddle in about 15 mins. I crawled under it last night and oil was on everything the tranny pan, transfer case, crossmember, bellhousing, engine block all the way up to the oil filter adapter and the exhaust manifold. I wiped it all down as best I could and let it sit for half an hour to see if I could see where it would be leaking from but after sitting there for half an hour nothing. So I ran the engine for about 10 mins. to let it warm up and get some pressure and could not see anything leaking while it was running or half an hour after I shut it off. I had to put in 2 quarts of oil to get it full again and drove it to work this morning, when I got here grabbed a flashlight and looked and no extra oil besides the residual that was still there slowly coming off. Was here for about 2 hours and checked it again and low and behold oil dripping off the back of the oil pan, front of the tranny pan, and bottom of bell housing. Doesn't look like a blown valve cover gasket because I didn't see any oil around it or around the head gasket, the only thing that I can think of is the rear main seal is allowing oil past it and into the bell housing and the flywheel is spinning it off and covering the inside of the bell housing and then after sitting for a while it drips down and out of the flex plate. But how am I getting oil dripping off the tranny pan and oil pan? Any body got any suggestions as this is my only car and need to get it fixed tonight and tomorrow because sunday it's only supposed to be a high of mid 30's.

[sector95]

Just a guess here, but have you looked at the oil filter adapter? If I'm not mistaken there are some seals/gaskets in the mount and assembly that may have started to leak. Oil at the filter is under pressure (that's where the pressure guage reads from) so if it's leaking it'll have some velocity behind it. The leak might not occur until the engine is fully hot, the oil has thinned to it's normal working viscosity and/or the leak opens up due to metal expansion as the engine gets hot. You bring it up to highway speed and your talking a good 40-50 psi. I wouldn't think a main seal leak would get oil up around the filter and onto the exhaust manifold. You also might have a bum oil filter seal or possibly a hole or leaking seam in the filter itself.

Mike
00XJ

[dave92cherokee]

Well got under it this afternoon and coated the entire engine, engine bay, tranny, transfer case with engine degreaser and then sprayed it down. Let it dry up some and made sure I could not see any oil leaking. Took it for a short drive around the block to get the engine warmed back up (burning residual degreaser creates ALOT of smoke and stinks like crazy) then came home and looked underneath. Only thing I saw leaking any oil was the oil pressure switch so I got a new one and replaced it when I got the old one out the plastic and metal parts of the switch had broken free so they could turn independently. After replacing it I haven't seen more oil but it was also 8 at night too. Tomorrow I'm gonna drive it a little bit further and then see if there's more oil or not. Biggest question I have is with a bad rear main seal will it simply leak out around the rear of the oil pan or will the oil leak into the bell housing and then from the flywheel spinning coat the inside of it and then slowly drip down? Hopefully I'll get my tax return this week or next and when I do I'm going to replace a few needed parts on it. 16 years old and about 13 of them probably didn't have any good maintenance done to it so trying to play catch up is a pain. About the oil filter adapter seals I have gone to every part store in town and the only thing that they have for that is the big o ring they don't have any of the small ones. But I was looking at it today and instead of a torx or allen bolt it's a regular hex bolt with what looks like a 1/4" washer that is holding the adapter on (resembles the design of oil drain plug). So have any of you seen this or have it on your jeep and does it even have the o rings inside it or is it just the main one? Thanks for all your help and I'll keep you posted to what I find tomorrow.

[sector95]

Well before you get all worked up about what *might* happen, see if you fixed the problem with the oil pressure switch ...sounds like the pressure sender was bad. My 2000 Sport with 90K on it has a seeping rear seal leak ...not bad but just enough to coat the tranny pan and everyonce in awhile puke out a 50 cent piece sized blot of oil on the ground. I've not seen any evidence the oil works its way into the torque converter housing.

If your not sure about the gaskets for the filter adapter, go down to the stealership; they'll be able to pull up an exploded diagram of it along with the part numbers ...they might even have it stock for you.

Mike
00XJ

[dave92cherokee]

UPDATE

Well so far so good I replaced the pressure sensor last night and after driving around last night and today don't see any new oil dripping down from anywhere. Hard to believe that as much oil as I had under the jeep all came from a small leak in the pressure sensor. But considering it was under pressure kind of makes sense that it would come out with some force. Now just waiting till I get my refund and when I do I'm gonna replace the oil pump as I've had low pressure since I've owned it, and while i'm under there I'll probably replace the rear main as well so I won't have to worry about it in the future. Hopefully all is well with the jeep again.