slight whistle on startup for 5 seconds then goes away?

[dezzdash]

anyone know what that would be?

 

[KraftyPg]

I dunno whether I'd call mine a whistle but I have a belt that has made a noise since the day I got it. Lube stick fixes it for about 7000ks then it's back to normal.

 

[JPMC]

Could be the viscous fan as they turn for a little bit on start up then don't come on till up to temp.

 

[Bluenavara]

My a/c does something like that on startup. Since day one.

 

[user 10312]

I to have slight whistle on start up, well it's more than just at start up, it's until the engine is warmish. Does sound like a turbo whistle but only audiable on very light throttle or even overun (off throttle)