Thought I had a rear main seal leak but noticed I was missing a "grommet?" on the back of my valve cover. Moved one from the front to the back and sure enough I have a leak where the grommet is missing. Probably going to get a whole set later and replace them all.


Side note - I already paid someone to replace my rear main seal for me .

 

Sorry you went through the misdiagnosis and expense.

Good news is YOU found it.

I wrote the following just to help avoid such situations.




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, people on Jeep forums who can’t see your Jeep from where they’re at, 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 02-26-2013

 

Sad part is I did all that but not that order. I made a note in my Jeep log book to go top to bottom front to back and to do the work myself alone if possible. Thanks