Do yourself a favor and read this before jumping on the rear main bandwagon:






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

 

Love it. Everyone is always trying to bash on the ol renix for no apparent reason.

 

Certainly not me....

 

Love your tips Cruiser your a wealth of knowledge with these renixes and honestly with this jeep in poor repair it feels a hell of alot more powerful than my 92 cherokee did. I love it and i cant wait to bring it back to full glory.

As far as the RMS thing. Nobody here suggested it i just suspect it as a possibility. I need to hit the entire underside with degreaser and pressurewash. I also just did the valve cover gasket but could only afford one of the crappy cork ones which i had trouble getting it to stay in place. It wanted to bow in on itself. So it could be a number of things. I was just saying that is what i suspect at this point and i need to look into it more because its an excessive amount of oil leakage. It could very well be as well that the marvel mystery oil and 5w-30 was too thin. The mystery oil thins up the whole thing and could allow it to seep out. Maybe i didnt tighten the valve cover bolts enough. I dont own a torque wrench. =) Thanks for sticin with me through this.

 

That's just a "canned" response I wrote up for RMS and oil leak diagnoses. It ain't the thin oil. Do as planned. Degrease and diagnose. Poor eyesight and a dim flashlight is all you need!!

 

Do your self a favor get the silicone valve cover gasket from felpro if ya didn't when you changed it.

 

Hi freegdr. Havent seen you in forever! You helped me out alot with my first jeep. Lol stripped out the spark plug socket on that one. My first ever vehicle.

I wanted the silicone or rubber one. They didnt have it in stock and i got impatient so took the cork one. It very well could be the problem itself. Just not sure how to go about cleaning around underneathe the valve cover to see if thats where the leak is. Any idea?

Ive heard pressure washing the engine is a bad idea. The only thing i could think to do since it isnt the easiest area to stick a rag in.

 

Shop around for the silicone one it the best way to insure no leaks . Climbing under and looking. only wayto be certain leaks not valve cover. Nothing wrong with pressure washing just stay away from any thing electronic.
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It's still a jeep 4.0 I honestly love both of the jeeps I've owned with the renix motor.

 

It seems no different to me than my 92 was.