N’Evening I replaced the open air filter with the normal one last weekend. With the open air filter one hears the intake duct extremely well. But now I noticed with the normal air filter that I hear the turbo from 2200 u/min. The turbo whistles when it is at the druecken. Unfortunately I can’t remember if this is normal or not. Can it be that the turbo has a leak somewhere? I also noticed that the loader has an oiled bit. Can this also be due to it? (I doubt it, but don’t ask a problem) I have the 3 dunen loops, which go to the small distributor at the air filter box almost 1 year ago. I don’t think it should lie there.