if you have access to a Tachometer.. a digital tachometer.. like on a digital dwell meter...
if you block the PCV flow at idle... you should loose between 50 and 70 RPMs.
this lets you know that the PCV valve you have is close to the proper calibration..
you will also want to unplug the PCV valve from the end of the hose and verify the engine will stall... or there will be a MASSIVE HISSING noise from the end of the open hose.. the PCV hose should have no restriction with the valve unplugged.
you should also have 13/32, 15/32 19/32 emission/PCV hose..
if you don't have enough PCV flow.. you could have issues like scuffed pistons.. broken or worn piston rings. a compression test is the next step.. followed probably by a cylinder leak down test..
during high speed or acceleration when the manifold vacuum drops.. there is not enough suction to handle all the blowby.. so it comes out the vents..
if you cover the breather opening.. if you have just one.. in 10 seconds covered when you pull your hand away.. you should hear a pop as the air rushes back in...
EDIT... yes.. without a PCV you will have oil vapors and residue coming out the breathers..
Last edited by 69612; 07-13-2016 at 12:38 PM.