VERY frustrating oil leak

[Sacredgroove]

leaking at backisde of valve cover on stock 4.2 84 cj7.
i have replaced the valve cover with normal gasket,double cork gasket, & the right stuff. it had an aftermarket aluminum cover i changed out to another when gasket changes didnt do the job but it is still pouring out the backside of the cover down the rear of the engine to the tune of a quart a day if i drive it alot.
ive switched out gaskets, a jeep speciality shop switched out gasket and put in "the right stuff" and i recently went back and changed to a new cover and cork gasket thinking maybe the old cover was warped to no avail. any ideas as to what could be causing this?
thanks!

 

[TwistedCU]

What are you using to seal the gasket?

 

[derff96963]

The only things I can think of is first is your PVC system hooked up and working. It is not it could be causing pressure to build up in the valve cover and push the oil out. Second is if there is alot of sludge in the valve cover not letting the oil to drain back into the pan fast enough. Third do you have a T-case drop? What the angle of the engine. I can't really think of anything else.

 

[Junkpile]

Don't feel bad, AMC couldn't get them to seal up either. Proof is in how many ways they tried over the years. They tried bolting it all the way around the outside, only on one side with center studs, no bolts with center studs, thin gasket, thick gasket, no gasket,........
I had an 81 that was the worst I've seen. I had to grind the sealing surface on the cylinder head flat, and run two thin gaskets.....one permatexed to the head and one on the cover. That was after tapping half of the holes for the outside bolts as that one didn't use them from the factory, it was only held on by the center studs.

An aluminum cover with a cork gasket and lots of sealant to hold it in place will fix it. You need to see if your cylinder head has the holes for the bolts around the perimeter of the cover, if not, use the cover as a template to drill and tap(or just tap if the unfinished holes are there) because the center stud mounting sucks. Use large washers, ground to fit, on the bolts to spread the load out across the cover and avoid warpage.

 

[Inspector-Gadget]

Hi-Ya, scaredgroove,

A look into Gadget’s crystal ball suggests that derff96963 is right on the money with his “check the PVC system” suggestion. I would add that you might also have a level of blowby for which even a properly functioning PVC system cannot compensate.

Given the several previous attempts to fix the oil leak by replacing the valve cover gasket, one of those attempts should have succeeded.

Beg, borrow, buy or steal a crankcase pressure tester.

Regards,

Gadget

 

[Junkpile]

RE:

If you haven't checked that yet.......well.....yeah check it, obviously. Just don't be surprised that even with all other components being good, it still leaks.

 

[Sacredgroove]

blowby and pcv could be it. im going thru air filters every 3 months but ive been chalking that up to the leak,could be from blowby originally causing the problem. ill look for a crankcase pressure tester.
it is sealed with permatex' "the right stuff" and valve cover is brand new.