'05 Silverado - Thrashing Machine

Anyone experiencing a strange "thrashing" noise coming from the engine compartment. Sounds like it is coming from the air conditioner and similar to bearing squeel, but at a lower frequency. Very annoying, especially at a traffic light.

Also, flapping noise coming from the upper windshield area.

I've heard both are known problems, but my dealer says - No way...

a lot of people have that noise coming from the windsheild after installing a bug deflector. if you have one on your truck that is what makes the noise.