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Blowby? Oil in the air-cleaner

Zoro

NAXJA Forum User
Location
Colorado
Lately I've been noticing oil on my air cleaner and oil dripping out of the oil breather hose right at the air-box end, what causes this and how can I fix it?
 
Cleaning out the small plastic line running from the top of the valve cover to the intake manifold, usually helps some. Make sure and blow in the hole in the top of the valve cover and check and see if thats plugged also.
Do a search, some guys have come up with some novel methodes to deal with excessive blowby.
But first clean out the small plastic scavenger line.
 
What year is your Jeep? See the MAD XJ article on updating the CCV tube:
http://www.madxj.com/
Get a good seal between the valve cover and the head. I think this is a main culprate of the problem. Air leaks in and unbalances the system. Oil then gets sucked into the air filter. Same if the CCV tube is pluged. I updated to a 91-95 Valve cover on my '88. With the 99+ CCV tube no more oil blow-by.
Tom
 
Zoro said:
Sorry, it's a 1990 XJ with a 4.0 & 5spd and 185k.
Thanks
If this is a reply to my '88 info, they are both Renix motors. So the setup will be the same. Mine is also a 5spd. Your should have an AX-15 and mine had a BA-10/5. Mine has 140K, probably more as the speedo cable wasn't working when I bought it.
Tom
 
My blow-by was a combination of the rear line on the valve cover being clogged and the snorkels on the inside of the valve cover were full of thick black gooey muck. Cleaned them out and good as new.
 
Thanks for the tips. I'm gonna get the vacuum hose kit and take the valve cover off, clean it and replace the gasket since it needed it anyway. The blowby ain't bad yet but I like to catch these things early.
 
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