Just wondering if anyone has experienced this and knows what it is. Whenever I have the climate control turned on and am driving at low speeds I hear a sound coming from the engine. It sounds like gr, gr, gr, gr. When I turn off the climate control the sound goes away. Just wondering if it is the serpentine belt or something else. Thanks.

 

I sometimes hear a faint hiss when the AC is on....not a gr. Pop the hood and see where it's coming from.

 

Are you sure it is not the sound of the small motor moving the middle vents back and forth? It does make a minor grinding sound as it operates.

 

I have heard the sound the vents make. It's not that.