Oil Leakage

When I park my 95 XJ on the driveway I see oil spots from about 1/4 inch to 3 inches in diameter (sometimes larger). Parked on the street, I consistently see 3 to 4 spots all about 1/2 inch in diameter. Seems to be coming from around the oil filter area. I thought it was either the valve cover gasket or the oil filter, so I replaced them both, doing a complete tune up as well. Oil still leaks. I think it's motor oil, but could it be something else? The T-Case? Also, lately, when I stop the Jeep, I can smell, very faintly, almost like the smell of burning oil. Any Ideas? All your help would be greatly appreciated.

Oil filter o-rings are a common culprit as well

oil pressure sending unit


rear main seal

If it were the oil sending unit or the rear main seal, what's involved in fixing the problem? How much is is going to cost?

I'm guessing the rear main seal....if it's the rear main seal...it should be fairly simple. The only major things you need to really remove is your oil pan. After that it's fairly easy. If you need, I can send you directions on how to do it. Let me know!!

If it's the sending unit, it's about 30-40 bucks if you have gauges, probably less if you dont, dead simple to do - just unscrew and replace. The sending unit is right there on top of the filter adapter. Should be very easy to clean off and spot leakage if it's there.

If it's the main seal, you need to take the oil pan off, replace the seal then get the oil pan back on. If your Jeep is unlifted, this will probably mean removing some parts of the front suspension and then jacking up the body to get the axle far enough out of the way of the pan. I forget which parts, only remember that the directions from the Haynes manual did not include enough to get the pan off my saggy baggy old 87, and I ended up taking a whole lot of stuff off! If the pan is stuck on, it can be a hassle prying it off without distorting it. You may also have to lower the pan a little, then remove the oil pump before the whole pan comes off. Once the pan is off, you can replace the seal, which is inside the rear main bearing cap. That part is pretty simple; the seal is in two pieces, so only the one bearing cap has to come off. If you work clean and don't use steel tools to poke out the upper half of the seal, you'll likely have no problems. Fel-Pro makes a special 2-lipped seal for worn crankshafts that works quite nicely. It comes with instructions to ensure you don't put it in backwards, too.

You then, of course, need to replace the oil pan gasket and get the pan back on. I have done this using a 4-piece Fel-Pro gasket, and will never do so again. Next time I will follow the recommendations of fellow Naxja members and get the Mopar 1-piece gasket no matter what it costs! The rest is just reverse of removal.

You might be able to spot main seal leakage if you take the tin cover off the bottom of the flywheel housing. A main seal leak will show signs of oil hitting and being thrown off of the front surface of the flywheel, where an oil pan leak will not.

My 95, now at 219 thousand miles, has developed a pretty fierce leak back there, so I am psyching myself to do the job again. It isn't rocket science, but it's tedious and occasionally frustrating. Budget a good long time to do it right.

thanks for all your help.