From our friends at Google.....
"It is critical that the parts of the PCV system be kept clean and open, otherwise air flow will be insufficient. A plugged or malfunctioning PCV valve by itself cannot damage an engine; however the blowby will flow up in a reverse fashion up through the crankcase air inlet and if there isn't a separate catch can or oil separator at that inlet, then the blowby will contaminate the air intake manifold. On boosted engines this can be a real problem. A poorly maintained engine's PCV system will eventually contaminate the air intake manifold with oil sludge and if both the pcv valve and the crankcase air inlet are blocked then the crankcase pressure will build to a level that will damage seals and eventually the motor."
The PCV is an inexpensive part that needs replacing on a regular basis (typically when doing a tune-up). Don't make such a big deal out of this. If it is dirty or sticking, change it and move on.
Originally Posted by Bronco Boy
