pcv valve ,why?

[Great White]

Pcv valve is suposed to prevent air to be suckt in to the "intake",not to stop air to pass out?
Or is it the other way?
saw a pcv valve from a other car that fitted my hooses but it would prevent air from coming out.
(hope you understand what i mean.)

 

[dogfriend]

I think the other way (but I'm not entirely sure of what you mean)

The purpose of the PCV (Positive Crankcase Ventilation) valve is to allow blowby (gases which have escaped from the combustion cylinders) to be pulled into the intake air and recycled into the combustion chamber again. This is done to reduce emissions to the atmosphere.

The PCV valve is a check valve which allows flow in one direction only - from the crankcase to the intake.

 

[BrooklynBay]

I think the other way (but I'm not entirely sure of what you mean)

The purpose of the PCV (Positive Crankcase Ventilation) valve is to allow blowby (gases which have escaped from the combustion cylinders) to be pulled into the intake air and recycled into the combustion chamber again. This is done to reduce emissions to the atmosphere.

The PCV valve is a check valve which allows flow in one direction only - from the crankcase to the intake.

This was very well explained, just like a definition in a dictionary.

 

[ExplorerDMB]

To check a PCV valve, pull it out and shake it. If you hear a rattle - its good

-Drew

 

[rookieshooter]

One other thing, after taking it out and shaking it to hear if it rattles or not. Spray it with something like carb cleaner. You be surprised how much crap comes out. A lot of times after spraying when you shake it again you can actually hear a difference in sound as the check ball seals better

 

[scucci]

Welcome to the forums Great White!
The pcv valve is closed to a small opening when high manifold vacuum exists. The valve opens all the way under low vacuum to allow crankcase pressure/gases to vent to the intake manifold. The pcv valve blocks passage to the crankcase when a manifold backfire happens to prevent crankcase explosions.

Roy