Engine Oil in the MAF


Apr 29, 2003
I've had oil creeping into the throttle body ever since I removed my valve cover baffle to install roller rockers. Lately, however, I've noticed oil dripping from my air filter when parked. The oil in is running all the way down from the t-body past the MAF and out the air filter.

Any thoughts? Is this a big no-no getting oil in the MAF?
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Well, you do not want oil in the MAF, but the bigger problem is all of the blow-by the engine is producing that is causing all of the oil vapor to condense in the intake and cause the oil to leak past the throttle body. Either the PCV valve is not working, or the piston rings are not sealing. Or you drive at WOT all of the time!
Thanks for the feedback. I removed the valve cover baffle because it interferes with the roller rockers.

Hissin, can you explain this catch can you recommend?

Does an oil breather cap still need to be plumbed back into the t-body like the stock cap?
Thanks for the feedback. I removed the valve cover baffle because it interferes with the roller rockers.
I guess my point was that you still need a baffle...

What is happening in your valve cover right now is .....
the oil is being tossed around due to movement of the rockers. Without a baffle, this oil is free to migrate up the filler neck, and into the TB...

I have been able to cut a thin piece of sheet aluminum and JBWeld it in for a baffle.
If you don't subject the JBWeld to any loads, then it will hold up pretty well...
Just don't try to 'adjust' the baffle after the JBWeld has cured.

Catch cans and separators will work well, but in my opinion... the baffle should be installed...
Jason is absolutely right. When I first read this, I hadn't comprehended that you removed the baffle. You have to get that back on there. Otherwise it's like having been stabbed and asking what the most absorbant bandaid is, when you really need to get some stitches and medical treatment.

But to answer the question, a catch can is just a basin with an inlet and outlet up high. I use an air/oil separator with the filter element removed. The PCV line goes through this - the air continues on and the heavier particles collect in the basin.

Good luck.