Re: SRT6 Superchager Rebuild Kit ?
At idle the 'draw thru air' causes the impellers to rotate, as the engine breathes and developes a low pressure "vacuum" on the outlet. Mechanically there is little resistance to moving.
Now if it is noisy, you need to address the problem SOON as the clearances are tight and if the bearings allow contact of the rotors, the repair is going to be more costly for sure. The case and impeller fit closely, its a real carefully assembled device.
Woody, Enjoy the day