Well... THERE'S your problem.
Thread Starter
Senior Member
Joined: Sep 2008
Posts: 897
Likes: 12
From: Sioux Falls, SD
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0L
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Make sure the CCV tube from the back of the valve cover to the intake manifold is not restricted.
Wouldn't hurt to do this:
http://cruiser54.com/?p=131
Wouldn't hurt to do this:
http://cruiser54.com/?p=131
Thread Starter
Senior Member
Joined: Sep 2008
Posts: 897
Likes: 12
From: Sioux Falls, SD
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0L
Ya. It's clear. It's almost that time for my '92 4.0. The blowby is crazy. I just re-routed the front intake elbow with a long hose under the front end somewhere. 
Capped off the air-cleaner box nipple also.

Capped off the air-cleaner box nipple also.
Thread Starter
Senior Member
Joined: Sep 2008
Posts: 897
Likes: 12
From: Sioux Falls, SD
Year: 1999
Model: Cherokee(XJ)
Engine: 4.0L
I built a catch can the other day. It just seemed to fill up with water and nasty oil and didn't flow enough I think. Started making oil spew from the dipstick due to extra pressure/poor flow. Once it gets above -4F I will redesign the catch can idea for greater flow. My simple PCV tube idea stinks at idle in the McDonalds drive thru.




