2.3L ('83-'97) Oil in the Air Filter

[Quaker]

Hello,

I have a 1983 Ford Ranger with a 2.3L inline 4 that I just finished rebuilding. And after driving it for a while I noticed that there is a good amount of oil in the air filter coming from the hose that connects it to the oil fill cap. It's my understanding that this connection is part of the PCV system to provide fresh air into the crankcase while the blowby is sucked back into the intake manifold. So I checked it out and found that air is flowing both out of the oil fill cap and the crankcase breather. I also checked the PCV valve and it was providing a vacuum to suck out the blowby. I am assuming that there has to be a vacuum leak elsewhere for air to be going out of both the oil fill cap and the crankcase, is this a fair assumption? any guess on where the vacuum leak could be? any other ideas why air would be coming out of the oil fill cap and in turn pushing oil into the air filter? Thanks for any help!

 

[cbxer55]

There shouldn't be any possible way for the PCV airflow to go backwards, especially if the PCV valve itself has vacuum. The only reason I can see for airflow to go backwards like that is excessive crankcase pressure that the PCV valve can't handle.

 

[RonD]

Welcome to the forum

Assuming carb 2.3l engine in an 1983 Ranger

PCV Valve may not be working like it should

And no, shaking it is not a "test" confirming its working, lol

PCV Valve should be plugged in to intake manifold or base plate on carburetor, it must be BELOW the throttle plate, thats regular vacuum, above throttle plate is Ported Vacuum and it won't work as designed

With engine warm and idling pull PCV Valve with its hose from the valve cover, put your finger over lower end of PCV Valve should have a vacuum there and RPMs should change a bit
If no vacuum then PCV Valve is bad


Yes, PCV valve should suck in the blow-by pressure created in all piston engines, so either PCV system is not working or you have way too much blow-by