High pitched whine from under the hood...

[lodit]

2001 C5 A6 4.2

Any idea what it is?

Comes on when the car is turned on, and dies out when engine is turned off.

Just started recently, never heard it before.

Not a fan, seems like it's something spinning at a lot higher rpm, hence the whine.

Thanks in advance for your input.

[oc-drop]

someone installed a supercharger and didn't tell you!

[lodit]

someone installed a supercharger and didn't tell you!

I do notice more of a grunt and grumble when accelerating...so perhaps you're right!

But unfortunately, no extra boost... :(

[PMR2.7t]

2001 C5 A6 4.2

Any idea what it is?

Comes on when the car is turned on, and dies out when engine is turned off.

Just started recently, never heard it before.

Not a fan, seems like it's something spinning at a lot higher rpm, hence the whine.

Thanks in advance for your input.

Had the same problem ended up replacing the secondary vac pump but only whined on cold starts..

[AudiSportB5S4]

Had the same problem ended up replacing the secondary vac pump but only whined on cold starts..

2nd. this is only on automatics

[lodit]

And how much would be a fair and reasonable price for parts and labor?