MicahCB

I have an oil leak coming from what looks like my rear main seal. Since I took this picture I've wiped down the area and it looks like possibly a little oil has came out from there since then. The weird thing is that the seal right behind the oil pan looks nothing like the the rear main seals that I've seen in on the videos. It's a 2001 Jeep Cherokee Sport 4.0L automatic rwd.

andrewmp6

Make sure its not leaking somewhere higher like the back of the valve cover.

BruceB

^ what he said....and the oil filter adapter

cruiser54

Here ya go.

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: “Crap 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.

diskman

Seconding what Cruiser said. Also, replacing a RMS on the 4.0 is NOT the end of the world. You don't need to "Pull the trans!" or "remove the engine".

The rear seal in the 4.0 is a split design and can be replaced with the engine and trans installed. Takes a good day of messing with the oil pan removal, but it's doable for just the cost of a new seal, quality pan gasket and some black RTV.

MicahCB

Thanks a lot for the help everyone. I'm now thinking it's the back of the valve gasket that's leaking. I found oil there. I wiped every thing off the rms and put a rag behind the valve gasket so it can't drip down to the rms any more. So I should know in a second for sure. I still haven't been able to figure out what that seal is I was talking about. Its only a half seal and its very hard. It looks nothing like the rms that I've seen in videos but it's right behind the oil pan. Anyone have ideas? I'll post another pic from a different angle below.

Oswalla

I think what you are describing that metal band on the rear most lip of the oil pan itself. It does not seal the pan. The rms can't be seen, til pan is removed and bearing cap.