Whining sound when ac is on

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Noquacks
Posts: 41
Joined: Thu Jun 29, 2017 2:18 pm

Whining sound when ac is on

Post by Noquacks »

People,

2009 BMW 328i, original owner, 70,000 miles, manual trans. When I shift gears with ac on there is a whining sound that increases with pitch matching the gears I am shifting. The sound matched 100% with the rpm's. But as soon as I turn off the ac button the whining stops.

AC is ice cold. Could it be a bad serpentine belt? Compressor starting to go bad (bearings, etc)? Maybe the spring tensioner on the serpentine belt?

Thanks, People.
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