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Replacement for always leaking Renix Oil Fill Cap?

jk333

NAXJA Forum User
Location
WA
On my 87 Laredo, it seems like nomatter, what I try, the Jeep always leaks oil out of the filler cap on the valve cover (4.0 Renix) I have replaced the cap a couple different times from different (Renix 4.0) Cherokees and even put a brand new one on there. Same thing, it leaks. It has no other oil leaks and its frustrating to have this one leak. I have replaced the valve cover before with another Renix era 4.0 valve cover and same thing. Does anybody elses do this? Im thinking about changing to a valve cover from a 91+. Maybe that will fix my problem? :helpme:
 
On my 87 Laredo, it seems like nomatter, what I try, the Jeep always leaks oil out of the filler cap on the valve cover (4.0 Renix) I have replaced the cap a couple different times from different (Renix 4.0) Cherokees and even put a brand new one on there. Same thing, it leaks. It has no other oil leaks and its frustrating to have this one leak. I have replaced the valve cover before with another Renix era 4.0 valve cover and same thing. Does anybody elses do this? Im thinking about changing to a valve cover from a 91+. Maybe that will fix my problem? :helpme:

The first thing you should do it make sure that your CCV orifice is clean and clear, if that system is plugged, then the crankcase pressure will push oil into some odd places. If that is clear then I would change to a later model valve cover.
 
The first thing you should do it make sure that your CCV orifice is clean and clear, if that system is plugged, then the crankcase pressure will push oil into some odd places. If that is clear then I would change to a later model valve cover.

Agree, ensure the CCV system is functioning correctly first.

There is a mod Cruiser54 posted to the valve cover: http://naxja.org/forum/showthread.php?t=1026666
 
I acquired a Technical Service Bulletin book the other day for 1988 and 1990. They also mention that the rear grommet and pipe for the CCV system allowed the pipe to stick through the grommet too deeply and to update it. Napa has that pipe and grommet for $8. I'd get that just for giggles, too. But, the true cause of oil in the air filter was addressed by the mod in the thread Joe provided above. Your problem may be caused by CCV pressure. That pressure does increase when the CCV system is allowed to pick up liquid oil and have it cake up in the small plastic lines.
 
Thank You guys. That makes sense. I'll check out the ccv system and go from there. :thumbup:
 
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