The only "check" I know of on a PCV is that it "clicks" easily when you shake it up and down. Its just a weighted valve that supposed to pop open when pressure builds beneath it.
They're usually cheap- if you're unsure, I'd just replace it.
However, if its stuck open your catch can should have alot of oil in it.
If its stuck closed, I'm not sure how oil got to the IM
.
You're sure the catch can is correctly hooked up, and funtioning properly?