Oil getting in the air filter

[BuzzV59]

A friend on mine has a 1990 Jeep Cherokee, 158,000 miles. Was looking at the engine and radiator for overheating problems, but noticed the fram air filter was soaked in oil. Looked to me like back pressure was pushing the to the filter via the vaccum. Oil had gotten all the way in to the throttle body. Any ideas?

[JDPascal]

Originally Posted by BuzzV59

A friend on mine has a 1990 Jeep Cherokee, 158,000 miles. Was looking at the engine and radiator for overheating problems, but noticed the fram air filter was soaked in oil. Looked to me like back pressure was pushing the to the filter via the vaccum. Oil had gotten all the way in to the throttle body. Any ideas?

Welcome to the AF Jeep Grand Cherokee forum.

This basic engine is used in several Jeeps so the fix applies to all.

The cause is at the PCV valve in the valve cover.

Either the PCV valve is plugged or the baffle inside the valve cover is carboned up.

This requires removal of the valve cover and a clean up of the baffle system inside.

Shouldn't take too long and you will need a new valve cover gasket and a new PCV valve.

On the other end, a clean up of the throttle body, all the duct work, vent tube and a new air filter is necessary.

Sounds like a leasure Saturday with a "couple" of beers

JD

[hoofan]

I have the same problem now too, but the air filter was not soaked, I just noticed a "spot" on it. Thanks for the help, I will take care of that this weekend...

Bryan