After replacing both AC and Accessories belts on last Saturday. "AC On" noise is still there. I did try to listen to any noise in front of car with hood open, I could not hear any special noise similar to the one heard inside when driving (accelerating/decelerating). No squeaking sound when AC is ON.

Could it be AC tensioner pulley making noise when AC is ON during acceleration/deceleration ?

Thanks.

 

Did you check the condition of all the belt wheel bearings while you had the belts off?

 

NO, I did not do that. I will do that soon to check, at a minimum, checking AC pulley bearing with AC belt off.

Thanks.

 

I replaced all 2 tensioners (AC & Serp.) along with idler pulley. No more noise/sound from engine bay when AC is ON. It is now back to "new" car sound

https://5series.net/forums/diy-do-yo...cement-147480/

 

Great news! Enjoy your quiet car again