Car: 1998 a4, 136,000 miles, Chipped (APR), APR DV, Carbino intake, millitek exhaust, tp

I only hear the noise when I let off the gas. It is a continuous, fast clicking/vibrating noise like metal vibrating on metal. Also accompanied with a bit of a pssshhh sound.
I also hear what sounds like a air blowing out (quite faint) when I accelerate coming from ahead and to the right of me if I'm sitting in the driver's seat (where the turbo is) - but might be turbo spooling?

After searching, some others said it was for sure the wastegate and I would have to replace the turbo. Is there a way to test the wastegate? Also, could it just be the wastegate actuator, and how would I determine this?

Could this also be caused by a bad n75 or diverter valve? Or maybe just a boost leak somewhere?

I definitely notice a loss of boost, but I don't have a boost gauge so I can't give you any readings. I want to make sure I eliminate any other possibilities before replacing the turbo.

Thanks!

this is just not correct, from what you are describing you may or maynot even have a problem.


so... you dont notice a loss of boost because you have no idea how much boost you are running? you need a boost gauge right now.


it could be anything or it could be nothing. from what you are describing it could be caused by someone being overly paranoid about noises, or it could be a simple boost leak. how is your idle? is it steady at 850rpms? i would ask what your vacuum readings are and tell you for sure if you had a leak but you dont have a boost gauge.