turbo winding up???
 

Hi all...I have a 99.5 jetta tdi with 225k. at idle sometimes the turbo will start winding up...you hear the whistle. any idea why that would happen? is it a problem? If I tap the accelerator it will stop, then may do it again in a few minutes. The rpms dont change when this happens either. I cleaned the intake this summer and made sure there is not a lot of oil in the lower tube. It runs fine and other than that there is no problem with turbo etc while driving. I just dont want to hurt anything and cost me a turbo or???
thanx
Q