626 mazda A/c under hood noise

[edwardh1]

8 yr old mazda 626 75k miles around town miles -
when air cond is off under hood noise from compressor area is louder, turn a/c on and noise becomes less- noise sounds mechanical its not belt squeal.
thoughts?
why quieter when a/c is turned ON?

 

[JHZR2]

Compressor clutch issue? Maybe there is a misalignment so the bearings chatter more - load them a bit and they all fall in line?

 

[Eddie]

I wonder if the AC idler pullys are at fault? Bearing clearence is excessive and when unloaded they rattle.

 

[Quest]

sorry, you'll have to find some ways/means to upload the sound (yotoob?).

Without that,we are just playing guessing game (and so many things under the hood can be at fault).

Q.

 

[edwardh1]

Originally Posted By: Quest
sorry, you'll have to find some ways/means to upload the sound (yotoob?).

Without that,we are just playing guessing game (and so many things under the hood can be at fault).

Q.


true, my friend had the power steering pump replaced and that helped a lot but the noise now still gets quieter when you turn on the a/c. based on that I told him its probably not the compressor, since it would howl when on. the mechanic told him he needed a new compressor. maybe its the clutch and they cant buy the clutch seperate?

 

[mechtech2]

The AC clutch may be flopping around a bit due to a weak or broken springs, or maybe rusted parts.