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Lots of oil in air filter....why??
Thread Starter
CF Veteran
Joined: Jan 2011
Posts: 2,550
Likes: 1
From: aurora colorado
Year: 1991
Model: Cherokee
Engine: 4.0
Lots of oil in air filter....why??
So i have lots of motor oil in my air filter... its puddled in the bottom of the box... i figured out the oil is coming from the hose that connects to the valve cover, and to the top of the stock airbox... i dont know what it is... anyone???
CF Veteran
Joined: Feb 2012
Posts: 1,206
Likes: 2
From: Southern Oregon
Year: 1990
Model: Cherokee
Engine: 4.0
It's a jeep thing. Mine does it to there are a couple options I'll do a little digging and see what I can find for you. Or you can search jeep Cherokee blow by in you favorite search engine.
CF Veteran
Joined: Feb 2012
Posts: 1,206
Likes: 2
From: Southern Oregon
Year: 1990
Model: Cherokee
Engine: 4.0
Heres one way
http://www.jeepforum.com/forum/f46/x...75/index2.html
And I have a mod from another member here on the forum that might work to actually FIX the problem rather then band aid it but I'm still working out how to get it on here
http://www.jeepforum.com/forum/f46/x...75/index2.html
And I have a mod from another member here on the forum that might work to actually FIX the problem rather then band aid it but I'm still working out how to get it on here
CF Veteran
Joined: Feb 2012
Posts: 1,206
Likes: 2
From: Southern Oregon
Year: 1990
Model: Cherokee
Engine: 4.0
I hope this doesnt break any rules but this is one of cruiser54's write-ups that has to do with exactaly this problem
Cruiser’s Valve Cover Mod
Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.
Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.
Cruiser’s Valve Cover Mod
Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.
Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.
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Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I hope this doesnt break any rules but this is one of cruiser54's write-ups that has to do with exactaly this problem
Cruiser’s Valve Cover Mod
Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.
Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.
Cruiser’s Valve Cover Mod
Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.
Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.
Thread Starter
CF Veteran
Joined: Jan 2011
Posts: 2,550
Likes: 1
From: aurora colorado
Year: 1991
Model: Cherokee
Engine: 4.0
Originally Posted by cruiser54
No rules broken. LOL. But, it should be mentioned that oil in the air cleaner housing can also be cause by the rear hose/tube of the CCV system being clogged or broken. Clean it or replace it and make sure the valve cover grommets are in good shape.
Thread Starter
CF Veteran
Joined: Jan 2011
Posts: 2,550
Likes: 1
From: aurora colorado
Year: 1991
Model: Cherokee
Engine: 4.0
Originally Posted by jakbob
also check your spark plugs/ignition system. i had the same issue, did cruisers mod and still had the problem. did a tune up, it went away
CF Veteran
Joined: Dec 2011
Posts: 4,006
Likes: 1
From: Pasadena, MD
Year: 1987
Model: Wagoneer
Engine: Renix 4.0
CF Veteran
Joined: Nov 2010
Posts: 5,839
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From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
For oil in the air filter, I always start with a COMPLETE freshening of the ccv system (crankcase ventilation).
Remove valve cover. Clean thoroughly. Replace both grommets and both CCV hoses. Available at parts stores like NAPA or the dealer for less than $50 for the whole shooting match. Replace valve cover with a new gasket.
THEN see where you are at.
You must eliminate a clogged CCV system as a possible cause before moving onto more complex possibilities like true blowby (piston rings).
Good luck and keep us updated!
Remove valve cover. Clean thoroughly. Replace both grommets and both CCV hoses. Available at parts stores like NAPA or the dealer for less than $50 for the whole shooting match. Replace valve cover with a new gasket.
THEN see where you are at.
You must eliminate a clogged CCV system as a possible cause before moving onto more complex possibilities like true blowby (piston rings).
Good luck and keep us updated!