mystery oil leak pics
Changed the oil for the second time (after only 250 miles) b/c of the weird buttery possible condensation I had found and the noisey start-up (lifters?) It's had a sizeable leak that I'm trying to source. I took pics from underneath today before wiping it down good. Doesn't seem to come from up top (small leak from oil filter connector) but seems to come from the area between the oil pan and transmission. Is that possible? what connects the two? As you can see there are 2 areas that drip one from the drain plug of the oil pan and the other from the tranny pan the whole bottom is coated in oil and drips onto the exhaust pipe.
I used Castrol high mileage 10-40, no additives yet. Engine noise like a Diesel lol. Should I add Lucas? Or Lucas oil leak stop? It seemed quieter on the last oil that had Lucas in it. Where else can I look for the leak?

I used Castrol high mileage 10-40, no additives yet. Engine noise like a Diesel lol. Should I add Lucas? Or Lucas oil leak stop? It seemed quieter on the last oil that had Lucas in it. Where else can I look for the leak?

Senior Member
Joined: Dec 2008
Posts: 831
Likes: 1
From: Punxsutawney Pennsylvania
Year: 1988
Model: Cherokee
Engine: Renix 4.0 I6
id say wipe everything clean and let it sit over night or let it run for a little bit and put cardboard under it to see exactly where it is dripping from
You can look under after you shut it off and see it dripping from those 2 places (at drain bolt and edge of tranny pan) After I wiped it down I started it up and laid underneath while running for a couple minutes and nothing...
Senior Member
Joined: Dec 2008
Posts: 831
Likes: 1
From: Punxsutawney Pennsylvania
Year: 1988
Model: Cherokee
Engine: Renix 4.0 I6
a common place for these things to leak is the verry back of the valve cover.. there is a bolt back there its hard to get to but it can be got to it just takes some patience and some moving around .. see if its leaking back there and if it is tighten it up and if its still leaking try a new gasket
CF Veteran
Joined: Nov 2008
Posts: 2,473
Likes: 9
From: Paso Robles Ca
Year: 1991
Model: Cherokee
Engine: 4.0
get a new drain plug gasket
but it looks like a main seal
but like said before it could be lots of things
like the valve cover gasket leaking in the back
Senior Member
Joined: Dec 2008
Posts: 831
Likes: 1
From: Punxsutawney Pennsylvania
Year: 1988
Model: Cherokee
Engine: Renix 4.0 I6
yeah i didnt add that.. the other most common leak on the xjs is the rear main seal.. its not hard to replace. id wipe it clean and start it up and get under there and watch for fresh runs or drips and trace it
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valve cover gasket is a easy and cheap replacement just make sure you get the rear bolt tight. it is quite common for them to blow oil out the back. The rear main is also quite easy because it is a 2 piece you only have to remove the oil pan as apposed to the trans
looks like the rear main seal, had the same problem on a 91 mustang gt, was gonna cost about $500 to fix, so i said **** it and just proceeded to dump about a quart every two weeks in and that 5.0 H.O. motor ran like a top! but it wasnt leaking that fast, if your putting in more than a quart a week, you should get it changed!
Newbie
Joined: Feb 2009
Posts: 2
Likes: 0
From: Reykjavik, Iceland
Year: 1998
Model: Grand Cherokee
Engine: 4.0 l
After changing the main bearing seal mine still leaked. So finally it was a head gasket leak between #3 and #4 cylinders on the right side. The gasket it self was not blown. Installed a FEL-PRO head gasket and took good care of installing the valve cover with cork seal and an adhesive to on side. Now my 1990 4l does not leak a drop.
I just replaced the oil pressure sending unit on my 93 XJ. Very common leak but would not cause that much. Its about a $10 part from NAPA. I also drip a good amount from my oil filter housing. I have the part for that but am not sure when I'm gonna get around to doing that. I would also have to agree with everyone else and say your rear main seal is going. While your under there check on the oil pan it self. I had an 88 and oil was permeating through the pan. Long shot but happened to me.
the valve cover gasket is easy enough to do so start with that and it is the least time consuming to. plus all most all xj's have a leaking valve cover as well. when done clean off the old oil then check for any other leaks.


