So today I started my car and hear an unusual sound at idle. I popped the hood and reved the car from the throttle body and noticed that I didnt hear the sound, which is like a metal to metal contact rattle, while reving the car up, but then when I let off the rattle started. It pretty much sounds like it is coming directly from my turbo, which has me worried. Is my turbo seeing the light at the end of the tunnel? During normal driving, the turbo behaves fine. Boosting fine and everything. I noticed that when im driving and spinning boost, everything sounds perfectly normal, but then I let off and cruise while still in gear and the sound happens, but now its a steady almost spuddering sound that slows down when the engine rpms slow down. I am hoping that its just going to be something loose. I put an Invidia up pipe on about 6 months ago. Any help would be great.