Hi,

Best example I can give about the noise:

While driving in a parking garage that echoes the sound my car makes, i used to hear the sweet sounds of a turbo spooling/whistling after every time i let off the gas.(no blow-off valve or anything; stock)

Call me crazy, but that sound has been replaced by a weird somewhat grinding noise every time I let off the gas???

What could this mean? Or are they even related? These beautiful works of art are somewhat problematic.

 

Check the turbo pressure relieve valve n249 if I remember correctly possible torn rubber boot in that control valve.

 

Thank you for the response, i will look into it this weekend! I will post the results