I Checked the vent hose from the top of the engine and it is clear. So I found the hose to the PTC nipple vavle. I removed the cold air intake to the turbo to get the valve out. The valve was plugged solid. After cleaning it out, it now passes lots of air. Do you know if in the powed off state, this is normal. Does the valve close when powered? How do you test the valve? Should I just buy an new valve to be safe?

PS, the cold air intake at the turbo coupling had distengrated to the point where it must have been sucking an awful lot of air. I definately have to replace it.