Funnily enough I had that valve replaced last week when I was getting the injectors replaced!!
Just been reading the up on the n54 pcv system and it had a note at the bottom of the diagram in bold saying that a faulty check valve can cause oil consumption & blue smoke and that the pcv system should be investigated 1st before changing turbos when these symptoms occur.
So, given I've already replaced the above breather valve is it literally just the cc cover that I need to replace?
Does the cc cover come with both check valves built in? If you look at the below link to RB's pcv thread you'll see a pic 1/2 way down page 1 of the 2 check valves I'm talking about. Given that they screw in I'm thinking they might not come as part of the cover?