Bad oil leak on 4.0 please help!
CF Veteran
Joined: Nov 2017
Posts: 3,700
Likes: 238
From: Groton, MA
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
Note that those 2 elbows are NOT the same part - one of them has a much smaller hole than the other. Make sure that the right one is at the right location.
I'm actually about to do the valve cover myself (with the fel-pro pictured) and bought all new elbows and grommets for the valve cover - The current VCG leaks a bit, maybe 1/2 a quart/3k miles.
It was leaking worse before I realized that a few of my valve cover bolts towards the rear of the engine were super loose. I snugged them down just enough to not be able to turn them by hand (not having the torque specs in front of me and knowing I'd be changing the gasket soon) and it helped "slow the flow" until I can get a chance to do the gasket.
Edit -- If you're buying one of the Fel-pro gaskets pictured, make sure the part number is correct for your vehicle. The box for the one I got for my 95 appeared to only go up to 95... now this could be bunk, I haven't double checked anything myself, but I feel it should be mentioned.
It goes without saying, so I'll say it anyway -- don't run the engine with only 3 quarts of oil in it! It takes 6, so keep it in the 5-6 range to avoid excessive engine wear.
I'm actually about to do the valve cover myself (with the fel-pro pictured) and bought all new elbows and grommets for the valve cover - The current VCG leaks a bit, maybe 1/2 a quart/3k miles.
It was leaking worse before I realized that a few of my valve cover bolts towards the rear of the engine were super loose. I snugged them down just enough to not be able to turn them by hand (not having the torque specs in front of me and knowing I'd be changing the gasket soon) and it helped "slow the flow" until I can get a chance to do the gasket.
Edit -- If you're buying one of the Fel-pro gaskets pictured, make sure the part number is correct for your vehicle. The box for the one I got for my 95 appeared to only go up to 95... now this could be bunk, I haven't double checked anything myself, but I feel it should be mentioned.
It goes without saying, so I'll say it anyway -- don't run the engine with only 3 quarts of oil in it! It takes 6, so keep it in the 5-6 range to avoid excessive engine wear.
Last edited by PatHenry; Feb 5, 2019 at 11:15 AM.
It is very easy to remove the two screws on the distributor cap and look for oil under it. There should be none. Asking as you are there make sure that the rotor and cap don't have much wear on their contacts. There is no need to pull any of the spark plugs' wires for this. At most just pull the middle wire to the coil.
The 4.0 doesn't have a PCV. The CCV elbows on top the valve cover and just that...elbows. The forward one that routes to the airbox isn't metered, but I believe the rear one that goes to the intake is. Clean the oil off, inspect the stock CCV parts (check that the elbows and lines aren't blocked), put them back on if good and see if it still leaks.
If you put a non-stock pcv valve on there that's probably caused the problem.
If you put a non-stock pcv valve on there that's probably caused the problem.
CF Veteran
Joined: Nov 2017
Posts: 3,700
Likes: 238
From: Groton, MA
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
There are 2 elbows. Did the old one that came off match the new one that went on? It's a pretty big difference, one is basically a hollow tube, the other has a very small hole at the base, so provided it looked pretty much the same, you should be good. (In other words, it's very obvious which one matches and which does not.)
CF Veteran
Joined: Nov 2017
Posts: 3,700
Likes: 238
From: Groton, MA
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
Looks like the back (rear of engine to intake manifole) one is the "with orafice" (aka, the little hole) and the front one (to the air filter box) is the plain old tube.
This is what O'Reilly's computer system said the pcv was...
Does this look like the right one?
there is a little amount of oil on the back part of the valve cover behind this little bastard
Had the ol lady crawl under it with her eyes, she said it was coming from the oil filter i put on last week when i changed the oil, checked the gasket it looked fine but had some seepage, now back to O'reallys to get a wix filter and pcv tube since it broke coming off, and some gaskets... valve cover wasnt leaking thank God since its the more expensive one
CF Veteran
Joined: Nov 2017
Posts: 3,700
Likes: 238
From: Groton, MA
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
Had the ol lady crawl under it with her eyes, she said it was coming from the oil filter i put on last week when i changed the oil, checked the gasket it looked fine but had some seepage, now back to O'reallys to get a wix filter and pcv tube since it broke coming off, and some gaskets... valve cover wasnt leaking thank God since its the more expensive one
It is obviously right at the point on the engine that would appear to be the filter leaking - especially to those less familiar with the engine.
Do the filter first - can't go wrong with WIX - and go from there.
CF Veteran
Joined: Oct 2018
Posts: 1,577
Likes: 279
From: United Kingdom
Year: 1995 RHD
Model: Cherokee (XJ)
Engine: 4.0l
CF Veteran
Joined: Nov 2017
Posts: 3,700
Likes: 238
From: Groton, MA
Year: 1995
Model: Cherokee(XJ)
Engine: I6 4.0L
Good luck bro!
Boxburn --- ugggg... that thing was a pain enough without extra stuff in the way. How did you get it - underneath with a lot of swearing and beer breaks?
Boxburn --- ugggg... that thing was a pain enough without extra stuff in the way. How did you get it - underneath with a lot of swearing and beer breaks?



