NateB1973

Hello All, I am new to this forum so please bear with me. I have an 87 Cherokee Pioneer all stock with 650,000 miles (yes you read that correctly). 4.0 Renix was rebuilt at 550,000 and it’s a 5 spd was Ba/10 and I converted to Ax15. We love this car and are the original owners.

Back in October it developed an engine leak. Since then I have had these items replaced.
RMS, Oil Pan Gasket, Valve Cover Gasket, Oil Adapter Seals, all PCV grommets, did not replace oil sending unit or distributor grommet since those areas were dry. Oil is still leaking. It comes out of the Bellhouse and blows back when driving. I have read several posts on this forum on here about oil leaks and are very helpful.

Sitting or driving around town the leak is small, doesn’t drip overnight if I wipe it down. After a 200 mile trip on the highway I need to add a qt and my under carriage is completely covered, I smell oil burning off the exhaust and rear hatch window has oil on it. So I clean everything off and drive on highway again, Valve cover seems to be dry, back of valve cover is dry, bell house is where the oil is coming from. In fact it’s so bad that the starter had oil coming out of its weep hole. The oil is coming from rear corner passenger side of oil pan up high.

The oil leak is much worse after highway trip. The engine otherwise runs good. Will cruise at 75 mph easily and no smoke from exhaust. Only smoke is from oil burning from its exhaust at times. Is it possible that the RMS wasn’t installed correctly or blew out again?

What else could be going on?

GzrGldr

Since you replaced everything it could be, the only assumption is that something wasn't done right. I would wager the RMS or oil pan gasket still leaking. I wouldn't think the RMS would cause you to lose a quart of oil on a 200 mile trip though. Losing that much oil, I would think that the gasket seal around the front of the oil pan didn't get seated properly. It's my guess since you mentioned the evidence being from the bell-housing back. Let us know when you get a million miles.

Saudade

Sorry for being blunt as you are a new subscriber here, but, yes, I'd suspect a bad install. It's quite easy to pinch a gasket, roll an o-ring, even put the top half of the rms in backwards.

The rear main bearing cap also needs a few dabs of silicone sealer to the chamfered edges.

You may need to drop the pan and check the rms.

You can go to https://Cruiser54.com for his Renix tips. There are also some technical publications for your model as well.

Welcome to CF and the Brotherhood of Renix!

NateB1973

Thank you for the reply. Will do for sure!

NateB1973

Thanks for the reply. Will check the RMS and oil pan gasket.

NateB1973

thank you. Will check it out. I love my Renix Jeep. It’s been a great vehicle but this oil thing has been the pits!

cruiser54

CRUISER'S MOSTLY RENIX TIPS

REAR MAIN SEAL DIAGNOSIS

OCTOBER 31, 2015 SALAD 3 COMMENTS

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. A little tip here. Rather than use a dizzy gasket, use an o ring instead. NAPA #727-2024. Tips 12 and 13 will help you get your distributor back in place correctly.

NateB1973

Thank you. Great info.
Nate