Hi I'm new to the forums. My 2013 335xi sedan AT with 1200 miles makes a sound once I let off the gas pedal. It almost sounds like a rattle. I'd say it does it about 70% of the time. Its definitely not the blow off valve because I've had a turbo car before and know what that sounds like. It does it once I lay off the gas. It Doesn't do it in park. Only in drive. Any ideas? I know the previous generation 3's attributed this to the waste gate but it was the MT? Mines an AT. I mean is this possible with a car that has only 1200 miles?