2005 Avalanche whistling sound when the engine is cold

**john humphries** · 10-23-2012, 08:38 PM

I get a whistling sound ,when the truck is first started in cool temperatures. Give it a shot of gas and the sound gets louder. goes away once the engine is warmed up.

**RayVoy** · 10-23-2012, 08:47 PM

Hmmm, just thinking of all of the times I've had that problem,
- could be an exhaust leak (I had a crack in an exhaust manifold that stopped leaking when the manifold expanded),
- could be a belt (an old belt, maybe 75 to 80 k miles, would squeal when cold),
- the radiator fans have clutches that let the fan turn only when the engine is hot (I've had fans with poor clutches that would be noisy when cold).

**Pikey** · 10-23-2012, 11:07 PM

Originally Posted by RayVoy

Hmmm, just thinking of all of the times I've had that problem,
- could be an exhaust leak (I had a crack in an exhaust manifold that stopped leaking when the manifold expanded),
- could be a belt (an old belt, maybe 75 to 80 k miles, would squeal when cold),
- the radiator fans have clutches that let the fan turn only when the engine is hot (I've had fans with poor clutches that would be noisy when cold).

I agree with all the things rayvoy mentioned. it Could also be a bad bearing in one of the pullys under the hood.

**Enkeiavalanche** · 10-23-2012, 11:57 PM

Does it have a CAI?

**ARMYtango** · 10-24-2012, 06:14 AM

I am thinking a squealing pulley.
I have the same issue right now with mine.
Only squeals when cold and first started, but goes away after warm up.
I haven't investigated it thoroughly yet, but if you find the issue yourself, please post it on here and let us know!