A/C bearing or ?????

[KenD]

I have a rumbling sound coming from the accessory side of the engine. It's almost a grinding sound, like gravel spinning. I have changed the idler pulley and the tensioner pulley to no avail. When I turn on the defrost, (too cold for AC yet) and the compressor turns on it seems to get rid of the noise. The noise is most prominent when the engine is under load in drive or reverse when I first place it into gear and still have the brake on. I have tried to listen as close as possible and when I place my head closer to the passenger side wheel well, I hear the noise better.

Any other opinions?

[ranebeen]

Cold or not you are going to have to turn on the A/C with car in park, and emergency brake engaged, with hood up to tell if it is the bearing or not. Old school is to take a long screw driver and put the metal end against the compressor and put your ear to the plastic handle. If it is the bearing, you will definitly be able to hear it growling. If it is still cold, you will have to turn your climate control down low enough for the compressor to come on. Good luck, and hope it is not the compressor because of big bucks.

[KevinW]

Remove the drive belt, reach behind the splash guard, and spin the A/C pulley. If it feels rough, it may be a good idea to bypass it until a new pulley bearing is installed. The failing bearing may generate a lot of heat, possibly damaging the compressor seal. A 6 rib, 73.9 inch belt should work fine (e.g. ACDelco 6K739).