strange noise upon shutdown

[Quadcammer]

Lately, my novi 2000 has made some weird "eerwp" noises upon shutting down the engine. Doesn't happen all the time, but on occasion. While its running, there are no odd sounds, and no problems with getting into boost. The blower doesn't knock, it doesn't really make any noise except for the smooth whine. Given that a centrifugal blower is a really simple piece of equipment, does anybody have any idea what could cause this?

I've had the thing for quite a while, its probably got about 20k miles on it (maybe 10k since a full rebuild), and its had a steady stream of clean synthetic oil run through it.

Any thoughts?

oh, and the belt is perfect, no sign of it being misaligned or damaged.

 

[Gallows]

Not sure of how the Procharger is setup but with my Vortech I had a idler with two bearing and a spacer/washer in the middle. The spacer was misaligned and pushed into one of the bearings causing a noise similar to what you are describing.

 

[01yellercobra]

The Novi is made by Paxton, not Procharger.

 

[Gallows]

:rollseyes whoops I knew that