CCV issues, why is there positive pressure??
Thread Starter
Member
Joined: Sep 2013
Posts: 101
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From: Machias, Maine
Year: 1989
Model: Cherokee
Engine: 4.0
So I have been hunting down a solution to my troubles with my Crankcase Ventilation system. There is plenty of vacuum from my intake manifold, but there still seems to be positive pressure in my crankcase, because the intake line that should be sucking air from the air box has been pushing steam and gunk and moisture into my filter.
I recently changed the ccv elbow at the front of my valve cover (the old one wasn't even the right one, so air and oil were leaking from around it) And Now it is nicely sealed. I just don't know why it is pressure the way it is. I have fixed the vacuum leaks that were obvious but what could I be missing??
I recently changed the ccv elbow at the front of my valve cover (the old one wasn't even the right one, so air and oil were leaking from around it) And Now it is nicely sealed. I just don't know why it is pressure the way it is. I have fixed the vacuum leaks that were obvious but what could I be missing??
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Cruiser54 on here has a valve cover mod that helps reduce amount of oil being drawn thru front elbo for renix get a hold of him....Post 25.https://www.cherokeeforum.com/f51/cr...153657/index2/
Last edited by freegdr; Dec 7, 2013 at 01:29 AM.
Thread Starter
Member
Joined: Sep 2013
Posts: 101
Likes: 0
From: Machias, Maine
Year: 1989
Model: Cherokee
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
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Herp Derp Jerp

Joined: Nov 2011
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From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
By "There is plenty of vacuum from my intake manifold" you mean you've checked that all of the plumbing between the rear CCV elbow and the manifold is clear, yes? Or are you going on something else?
^^^ Good mod (apparently).
Junk. It will fill with oil and not filter the air sufficiently. Plus if it gets wet you'll be in bad shape.
lmao
Cruiser54 on here has a valve cover mod that helps reduce amount of oil being drawn thru front elbo for renix get a hold of him....Post 25.https://www.cherokeeforum.com/f51/cr...153657/index2/
lmao
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
a breather filter on the valve cover would be just fine for a crank vent. Just make sure to plug the hole on the air box
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
No throttle body suction draws thru tube under acceleration when theres no vacuum present at ccv tube. It lets crank case pressure blow out but its not being sucked out like oem set up does.



