Madmike9494

I drive a 1999 XJ Sport with no performance mods. I have had a leak for a couple years. It seems to drip only after shutting off the jeep. Any ideas? I'm getting ready to replace bushings and whats the point if theyre going to be ruined again by the oil? I have'nt found a specific source of where it's coming from, but will post it when I find it.

stock95sport(for now)

common leak area are Valve covers, rear main seal, and Oil Filter Adapter (which i dont think your XJ has) also oil pressure sending unit, but those leak under pressure. i'd say either rear main seal, valve covers or oil pan gasket if it drips when draining into the pan.
Hope you get it figured out!!

ZINGGG

Pretty sure all XJs have an oil filter adapter.....

Anyways, degrease your engine, take it for a short drive and then pop the hood and look around again. Start with looking at the valve cover gasket, then the oil pressure sender, then oil filter adapter, then oil pan and rear main seal.

Don't jump the gun on the rear main seal just yet. Make sure it's not dripping from higher, causing it to simply mimic a rear main seal leak

stock95sport(for now)

yeah. idk, i was thinking the later ones got rid of the OFA, but thats the HCV, lol....my brains dead from work, sorry!

ZINGGG

Haha it happens, won't hold it against you

XJ_STRONG

How bad is the leak?

Fred/N0AZZ

Yes the oil filter adapter O-rings are a very common problem and on my 99 as well. You will find this is a very common problem with all of these adapters leaking and needing the O-rings replaced by I would guess 90+% of the XJ owners. Do a through cleaning of the engine top to bottom so you can see what's going on for sure first.

I was told my rear main seal was out also but it was not, it was the valve cover gasket leaking down the rear that made it appear to be it. Sounds like it may not be all that bad to take care of.

cruiser54

Here's how to find it:




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

Fred/N0AZZ

Damn Cruiser that rundown should be a sticky almost the way it reads "Right On" the money.

cruiser54

Post 15 in my Tips