No amount is considered "normal". Any blowby seen there would either indicate a problem with the PCV system or an engine that is just worn out. The filler cap should be air tight so I don't know how you would be seeing that anyway. If you are running the engine with the cap off, that's not going to tell you anything. If the air filter is not getting any oil on it, you should be OK.
Saturday, April 5th, 2014 AT 11:47 AM