So I will start from the top. I have recently been doing some DIY on my 98' XJ first thing I did was replace the valve cover gasket, second cleaned NSS, changed oil replaced oil pressure switch, change tranny fluid. Before I changed the trans fluid I degreased the motor from top to bottom, underneath around the tranny pan and the bottom end of the motor...all the places I could see and get to. Today when I changed the trans fluid I noticed some fresh oil on the bottom of my starter, oil filter and even a little blow back on the tranny pan. Any ideas what this could be?? I don't believe it's from the oil filter there is some on my oil pump and I looked a little closer at the bottom end and noticed some there as well. Any suggestions would be appreciated or has any else had these issues. Thanks in advance you guys have came through for many times before and it's appreciated much!!!

 

Check the oil filter adapter plate. They're notorious to cause nuisance leaking. Do you have any oil leaking at the inspection plate on the transmission?

 

I am assuming that the oil adapter plate is the receiver for the filter? And I'm not sure what inspection plate is....sorry I am learning.

 

I may be wrong with what I called it as the adapter plate. I'm referring to the part where the oil filter actually screws down onto. It should also have the oil pressure switch screwed into it.

The inspection plate, is located underneath. Where the engine and the transmission mate together. Directly underneath at the point in the middle, should also be across from the oil plug, there will be a removable plate.

 

Yes there was some oil there and some old gunk.

 

Okay, try spraying brake parts cleaner in both of those areas. Drive it for a day or so, and check back.

 

If there is a leak which of the 2 do I want ot to be?

 

If its leaking at the adapter, it's an easy fix. Id hope for that, if leaking down below that could point to a leaking rear main seal, which is much much more involved

 

If its the adapter is a replacement or a gasket replacement? Yeah I figured that was going to be the answer on the rear seal. Hope it's not that, that requires removing the oil pan and more right?

 

　
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. "$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 9-15-2012

 

I have replaced the valve cover gasket, and oil pressure switch, I guess I need to look into the oil adapter seal, and distributor seal. I had cleaned with degreaser a couple of weeks ago after an oil change, when I did the trans fluid today I noticed some on the bottom of my oil filter and starter and on the side of the oil pump.

 

Oil pump is inside the oil pan. But, the oil filter adapter seals are a common source of leaks. Keep us posted.

 

Will do.... sorry I thought the oil pump was just beside the filter where the pressure switch lives. I'm new to all this stuff. Thanks for your help/advice

 

Enjoy your Jeep and keep us abreast of your progress.

 

Well I did some cleaning today and cleaned up the residue around my oil filter. Looking at it closer I had oil between my block and distributor cap and on the oil filter receiver where the oil pressure switch is..nothing on top it was all underneath. Suggestions????