[Loud whistle/blow-off after engine is shut off]

I ordered a new valve cover. It came with the PCV-valve, gasket, and all the bolts. That fixed the problem.

I would like to add some pictures here, but max 114,77kb?? 

[Loud whistle/blow-off after engine is shut off]

Hi,

I have a 2014 Insignia with the 1,6L petrol engine. It has a turbo.

When I turn off the engine, It seems like it is huffing and puffing for some seconds near the throttle body. Almost like the turbo is still pushing air and I can hear there is air escaping somewhere.

Other than that the engine is fine, but occasionally (not often) there is some minor vibration at idle. At higher revs it is perfectly fine.

What is going on? Perhaps it`s the blow-off valve going bad?
This car is well maintained with only 60.000km on the clock.