Pull the inlet tube off and check for shaft play on the turbo. If I had to beat its time for a new turdo. Mine died a painful death after numerious passes at the track, my first visit with the car, that was a bad sign of things to come. Thing was it held 15psi fine just would smoke after a few times into boost. Drove it like that for a few weeks until the scream was ticking me off. The scream was the wheels eating into the housings.