Compressor noise may be the belt tensioner

[June]

This year my car has developed a noise between 1500 rpm to 2500 rpm which changes pitch depending upon the rpm. It went away with the compressor off. It turned out to be not the compressor at all, but the serpentine belt tensioner.

I am really mentioning this because I am told if the tensioner fails and the belt wraps behind or around the balancer it will in most cases break the timing belt destroying the engine. All over a belt tensioner! One sign that clued me in on the tensioner was glittery and black fluff building up above and below the pulley and also around the center of the pulley easily visible with a good flashlight. My car has 162K on the odometer.

If you have a strange wine, check out the tensioner pulley before condemning the compressor. My mechanic said the compressor puts extra stress on the tensioner causing the wine in the early stages of pulley failure.

The replacement requires the removal of the balancer pulley on the T6 and 2.9. The job at Volvo pays 1.8 hours so if you aren't going to attempt this yourself, dont let your mechanic overcharge you as my car was on the lift over 3 hours though the dealer book only allows 1.8 hours to be charged. The new belt, tensioner, and labor cost me $570 at my dealer. Of course all genuine Volvo parts and now the tensioner has a lifetime replacement warranty. June

[RickHaleParker]

I have had lots of strange wines but my tensioners never whined about it.

[June]

I have had lots of strange wines but my tensioners never whined about it.

The wheel/pulley on the tensioner. Surprisingly the pulley was wobbly loose. It only made noise while the compressor was on was the strangest part. June

[RickHaleParker]

It only whined when it was under pressure ... perhaps it needed another glass of wine to take the pressure.

[June]

It only whined when it was under pressure ... perhaps it needed another glass of wine to take the pressure.

June