Annoying whirring sound

[rlw001]

My car has an annoying whirring sound from somewhere under the hood. I cannot determine the source. It seems loudest when I put my stethescope on the fuel rails (especially from the MAF end). Weird? When I put my stethescope on the valve covers or engine block the sound is much quieter than the fuel rail. The sound does vary with engine rpm. The car is running great except for this sound. Any ides?

 

[masho95]

If the sound varies with engine speed I'd start with the most logical components associated with it. Accessory belts, pulleys, and timing belt. And overtightened timing belt will make a slight whining noise.. Ask me how I know that... lol

 

[stevemainian]

Thats your supercharger man, duh!

 

[Speedy_91_SHO]

Me and SHORacer14 both had the whirring on our old +'s. It was the tensioner for the accessory belts, the bearings had gone bad/got gummed up. Look at this as well as the tension on the belts. If you have just replaced a belt, I would suggest that where-as if you haven't touched the belts in awhile, I'd look at the bearings.

 

[SeanMc]

Mine is currently whirring. I need new tensioner bearings.