Another post about oil in the air cleaner...

[markindy]

I've read many posts about the PCV system, and getting oil in the air cleaner.  Most point to a solenoid that controlled the PCV valve as the culprit, but my '83 Eagle doesn't have a solenoid.  The line from the PCV valve goes directly to the base of the carb, with a T-connection going to the evap cannister.  After a long highway drive, oil was dripping out of the the snorkel of the air cleaner, and the filter was saturated....but the car still ran fine.  There was also some oil on the hood insulation, which I think likely came from the the dipstick tube.  Vacuum is strong at idle and the car accelerates and runs smoothly. 
The only other thing I see that could cause the engine to pull air through the crankcase breather is the secondary "flapper door" on the snorkel.  What does it do?  I understand the one that directs heated air....but the other doesn't seem to do anything other than completely block air from the snorkel. 

[89 MJ]

Is your PCV working properly? You should be able to remove it and hear a rattle when you shake it.

[MIPS]

When I rebuilt my carb I found that oil and deposit build-up had restricted the PCV port on the carb which meant the PCV valve was fine but the vacuum itself was weak.
The other thing was my PCV oil issues were attributed to excessive blow-by, which if you are getting spray out of the dipstick tube, I got bad news for you.

The only other thing I see that could cause the engine to pull air through the crankcase breather is the secondary "flapper door" on the snorkel.  What does it do?  I understand the one that directs heated air....but the other doesn't seem to do anything other than completely block air from the snorkel.

The inner flap opens whenever the engine is running and closes to prevent evaporated fuel vapor from making its way out of the air cleaner. The heated air duct isn't part of the PCV system at all and just allows the engine to pull warm air from around the exhaust manifold (assuming the metal hose and the manifold shroud are still there) when the intake air is too cold.