Scousebil

Hi just wondering if anyone can help with the most likely source of this oil leak on my 96 XJ 4.0l. I'm fairly certain there area a couple of leaks but the worst seems to be from a small rectangle shaped tray under what i think is the gearbox. I've attached two pictures which aren't up to much - the car is facing to the right. There is a crossmember which is covered in oil and the ground directly underneath is too. It seems to be coming from this ribbed rectangle which looks dry in one of the pics because of the flash but is actually also soaking with oil. Most likely cause??

X1997J

Could be rear main seal, oil pan gasket, tranny gasket, tcase gasket. Also a common spot for oil leak is the oil filter adaptor and check all your lines. Is the oil brown or redish?

Scousebil

No I don't think it's transmission fluid

Scousebil

Where about is the rear main seal?

Scousebil

Oh just looked it up on Google images and yes that's leaking but I don't think it's the main leak - seems to be further back than that

EZEARL

http://cruiser54.com/?p=96

cruiser54

Hey Quickdraw!! Nice work!!

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.

EZEARL

So simple even a caveman can understand it.

cruiser54

That's because a caveman wrote it!!!

EZEARL

LOL

Replaced my v/c gasket for the frst time since I've had my XJ. That Felpro gasket and grommets are NICE. Even beats cork and Indian Head!

cruiser54

They're great.

Scousebil

Ok brilliant thanks for the advice fellas. I know the oil will run down the engine to the lowest points but there's that much of it under there I couldn't put my finger on the source. The oil filter does seem to be leaking tho as can be seen in this pic so good call. However I still think the main leak is coming from further toward the back of the car and dripping onto that cross member. What is that ribbed rectangular tray?

Also, I checked the dipstick and there seems to be too much oil in it. I bought this a few months ago, drove it home, parked it up and never used it since - only knew about the oil leak because it's on my Dad's path and he was whining about the oil - had to throw a bag of cat litter under it. Hope it hasn't been overfilled and the pressure has blown a few seals ...

Scousebil

Tbone289

The ribbed rectangular tray is your transmission fluid pan.

Scousebil

I thought as much. It has this weird squidgy thing on one end near the gasket...