A/C problem

well heres the scoop. to make it short and simple when i turn the A/C off theres a loud high pitched rattle coming from under the hood where all the pulleys are(front of engine) when the A/C ON the sound goes away. i dont know if its a bad pulley or a bad A/C unit.

it would seem to make more sense that when i turn the A/C on the sound would come not when i turn it off.

any ideas?

i can possibly get a video/sound clip if youd like

Check the pulleys themselves particularly the belt tensioner. When the AC is on there is more tension on the belt. When you shut it off the tension is released and then you hear the noise.

sounds like the compressor clutch bearing to me. It may need to be replaced. Some shops can do this without even evacuating the system.

Check the pulleys themselves particularly the belt tensioner. When the AC is on there is more tension on the belt. When you shut it off the tension is released and then you hear the noise.



how do i go about checking the pulleys and tensioner

also how do i know if the clutch bearing is bad.

you take the belt off and spin each pulley by hand, feeling for binding or roughness.