Oil leak...problem or normalcy?

Bought another XJ...1992 4.0 HO AW4.

Its leaking oil...it leaves what looks like a decent sized oil spot every time I park it...even for a short while....but I check the oil every time I get gas and its not losing a significant amount...its been a month and I havent needed to add any. Its almsot like whatever is leaking out of it is just landing in a fashion that makes it LOOK like alot of oil but actually isnt...

To give you a measure I'm used to small oil leaks leaving like literally drops of oil on the ground...this is leaving a spot that is 2-3 inches wide.
I'm kinda ignoring it but in the back of my mind I'm afraid its gonna blow up cuz I'm paranoid like that.

It feels like it runs perfectly fine most of the time...but here are the few abnormalities I've noticed
It sometimes randomly has problems cranking...
The oil pressure reads normal...just replaced the sending unit...it used to read high before that.
Very rarely after driving it a long time it spits up some coolant while its parked...but I think thats normal.

Just a note from other posts Ive read...oil is normal color...not milky or anything like that...

Anyways after all that...is there any way for me to confirm that this is just some harmless leak or if this is something serious? Any tests or anything like that? I'm just trying to avoid anyting catastrophic.

As long as you keep your oil level up, you're OK. IMHO, it's just a little bad when it comes to parking on someones clean driveway that you don't want to piss off. Or possibly the fishies in the streams the parking lots run off into. But obviously you're not the only one. If it's the valve cover or oil pan, it's not that hard to fix.

Is there oil on the underside of the hood? Or anywhere else under the hood. If so, check, repair, replace the valve cover gasket. On my bros 91 XJ it was leaking and hitting the fan causing splatter everywhere under the hood. Also left oil puddles where ever he parked it.
If you do take it off though be sure and clean the underside of the cover. You'll be surprised how much crap accumulates on it.

Like winter said, its an easy fix. The hardest part we ran into was wiggling the cover from under the throttle wires that run over top of it. Its fine taking off but fitting it back under with gasket sealant on it was a bit messy. We were tipping a few then. Putting the sealant on the gasket that we had put on the engine would have been smarter and less messy. Not bad at all.

Hard to say ,not alot of info. But, my money is on a rear main seal leaking.

Have it checked by someone you trust.

Nick

hanaxj87 said:

Have it checked by someone you trust.

Click to expand...

Unless you have no aptitude for working on the Jeep.

Otherwise you should completely clean your engine and engine bay with something like Simple Green. Clean the sides top, bottom, front and rear being careful to avoid things like your throttle body (TPS etc.) and other electrical stuff. Clean between the oil pan and the tranny too. When it's nice and clean, take it for a short drive. Then crawl under there and check for leaks. Put a clean newspaper or piece of cardboard underneath to further isolate the leaking.

Back of head leak = valve cover gasket (best case)
Passenger side by oil filter = Oil Filter Adapter O-rings (not great but fixable) $18-20 parts - $200 labor
Between engine and tranny = Rear Main Seal (worst case, yet totally fixable) $15 part - $600 labor
Front of engine = timing chain cover gasket (meh).

...and then there's the possibility that the oil pan gasket is leaking. You'll never relly know until you can SEE where it's leaking. Then, practically, one ounce of oil looks like a LOT on the driveway, but you don't know how much is leaking while driving. So, like said above, keep a close eye on oil level until you determine the problem.


...and bye the bye I am anal about leaks, yet I still have them, so to some extent it's normal for and old Jeep to leak a bit.

^^^What he said.. Only thing he missed is the oil pressure sender, they tend to deveolpe leaks, mounted to the side of the oil fiter adapter on mine. A little bit of leaking is normal. But when you start getting spots bigger than a quarter, overnight, I'd start looking for something to fix. Mine is wet underneat but drops dont make it to the ground. When they do I'll fix the leaks.

Lotsa good info...thanks! Oil level is still normal and I havent seen any oil spots all weekend...prior to that there was a spot EVERY time I parked it...

Interestingly enough the top of the valve cover looks alot cleaner than normal.

Next time I see a leak I'm just gonna try the deal w/ cleaning the engine...I'm sure the problem will arise again...I'll post when I figure it out.

EDIT: 1 more thing...I have another theory. The guy who owned this before me didnt drive this Jeep much and was driving it on lower than normal oil levels cuz the sending unti was leaking. This Jeep had a few little quirks that seemed to go away this past weekend.
Is it possible the Jeep was demonstrating these problems just cuz it was sitting alot and the few times this guy did actually drive it was doing so on low oil...and that these problems just finally 'cleared out' because I've changed the oil, replaced the sending unit, and been driving it regularly?