Oil in my Air Filter?
 

Ok I blew off one the lines running from my tranny to my rad it was running so the fan made a huge mess with the tranny fluid. I fixed the line filled the tranny all is good driving shifting right I took my airbox apart and checked my filter it has deffinetly got what I think is oil in it i'm planing on changing it and watching it so I know if it was the transmission fluid explosion under hood or if I actually have oil leaking into my air box. If it is oil in my airbox what kind of problems am I looking at.

Re: Oil in my Air Filter?
 

Yes, they pretty much always have oil in the airbox. Depending on the year, the PCV system didn't pull enough fresh air through the crankcase and the blow-by would puke oil into the airbox. I did a couple mods on my last Cherokee because it was high mileage and kept soaking the air cleaner with oil.

All in all, common problem.

Re: Oil in my Air Filter?
 

What were the mods as mine is high mileage as well and i'd like to keep it running as clean as possible until I can park it and overhaul it. If you don't mind sharing your secrets and knowledge that is

My solution
 

if you have one like I had, there is a teeny (like 1/8") vacuum line going from the intake to the valve cover. That is not enough airflow to remove the blow by through the intake and the excess goes into the airbox. Mine was an '88 4.0L

Here's what I did, sorry the truck is gone and I have no pics to help...

1. change out the vacuum nipple in the intake to accommodate a 3/8" PCV hose.

2. Get an 85? chevy 350 PCV valve and a grommet to fit your valve cover. This may take a little hunting through the "help" products rack at canadian tire or napa or something. You may have to match the outer diameter of the valve cover and hog out the rubber to fit the new valve.

3. run a 3/8 hose from intake to new PCV valve.

This gets you a metered pcv flow at idle, but a large flow at cruise and low vacuum (load) which pukes the oil (blow-by) in the filter.

This may be enough and you can stop here, but depending on your blow-by levels, the above may not be enough to totally stop the oil in the airbox.

I added a K&N crankcase breather and removed the pipe from the valve cover to the airbox completely. It does clear the hood but it's close.

I hope you understand what I am talking about!

Good luck

Jet