Need Help. Have Whistling Noise Coming From The Engine Bay

jaslo · January 17, 2008

I have a 01 silverado. In the last couple of months, it seems like I have a whistling noise and it is related to how much I am on the gas. It is not in the radio, and its not wind noise. The noise gets a higher pitch the more I press on the gas, and when I let off it dies down. It also does it, while it sits in park. I know its hard to explain this noise, but I would like to know if anyone else has experienced this and what is the fix for it. Thanks

cerbomark · January 17, 2008

stick your head under the hood (while parked ) and have some one gas it, and see if it s the alternator (bearings) or AC (bearings). I had one make noise just before it finally froze up.

jaslo · January 17, 2008

stick your head under the hood (while parked ) and have some one gas it, and see if it s the alternator (bearings) or AC (bearings). I had one make noise just before it finally froze up.

I already did that. And I did not hear it. Maybe I need to do it again? It shouldn't be the a/c, because its not in use right now anyway, with it being winter. Or would it?

Bish · January 17, 2008

stick your head under the hood (while parked ) and have some one gas it, and see if it s the alternator (bearings) or AC (bearings). I had one make noise just before it finally froze up.

I already did that. And I did not hear it. Maybe I need to do it again? It shouldn't be the a/c, because its not in use right now anyway, with it being winter. Or would it?

AC still get's used anytime defrost is on to remove humidity from the air. I'd guess alternator bearings too as that's what mine sounded like before I replaced it.

BowTieDude · January 17, 2008

The AC compressor pulley bearings are in use whether the compressor is engaged or not. The noise could also be from the idler or tensioner pulleys. One of mine is making noise right now, but only when RPMs are above 1,000 or so.

ace ventura · January 17, 2008

Mine did that but it only turned out to be the belt.

07Graystone · January 17, 2008

Have you recently replaced your PCV valve with a non-GM unit? I've had a whistle/buzz due to this.

jaslo · January 18, 2008

No, I haven't replace the pcv valve. The whistling I get, goes with the rpm, the higher the rpm, the higher the pitch. Was wondering, should I have a mechanic get this checked out, or just drive it until something goes?

Darkanion · January 18, 2008

It might be a vacuum leak..? That would explain the pitch changing when the RPM's go up, since it would be trying to suck more air in.

cerbomark · January 18, 2008

still think it s along the belt, alt, ac, fan, line. You should be able to locate it if it s along those lines.

jaslo · January 18, 2008

Well, I will try to look at again tomorrow night, see if I can see anything else.

3n8fan · January 18, 2008

No, I haven't replace the pcv valve. The whistling I get, goes with the rpm, the higher the rpm, the higher the pitch. Was wondering, should I have a mechanic get this checked out, or just drive it until something goes?

Mine did the same thing and in the last week it has totally disappeared and I have no idea how or what caused it. Just waiting for it to reappear.