"Woooo"-ing noise when A/C is on
 

My 96 SSEi:

I hear a humming (sounds like a "wooooo") noise when I turn my A/C on. It seems to go along with the engine's RPM. When I turn off the A/C, a second later the noise stops. The noise is constant while the A/C system is on. Im wondering if mayby the bearings in my compressor is going bad. I can feel the hum/vibration through the gas pedal.

I took it to a mechanic and he had a listen, and when he did he thought he heard it from the water pump. But it doesn't make sense, since it should be making noise even when the AC is off.

Whats your take?

There is more strain on the belt with the AC engaged. This might be belt only noise...however if you want to get it figured out and know for sure. I would go to Sears and spend $15 on a mechanics stethescope. Head home and be very careful not to touch the belt or moving pullies, and listen to each item. When you hear the whooooing you'll know which item's bearings are probably getting worn. If you don't hear anything..it's most likely just belt noise.

X2 on the mechanic's stethescope recommendation. They are very inexpensive at Harbor Freight if you have one near you.

How hard is it to exchange the bearings on the A/C compressor, or does the whole thing have to be replaced?

My brother and I just put a new AC compressor clutch on my 95. This includes the bearings that were also making noise on mine. It was not an easy task. I think the hardest part was finding a pulley puller that fit. Lucky for me I know a mechanic that had the one I needed. After removal we had alot of trouble lightly taping the new one on, and getting the hub to fit over. I would not recomend this job. This did fix the problem noise though. Good luck.

Thats the thing, im trying to avoid spending $360 on a new compressor just for a bearing after a slew of unexpected expenses and an accident recently.

Looks like ill be looking at just getting a new clutch to avoid pulling/pressing the bearing. Does the freon have to be recovered before replacement?

it shouldnt as long as you don't remove the compressor from the vehicle

The bearing comes with the clutch assembly. You will have to pull it off with a puller and then reinstall either with a big socket or maybe the puller if it allows for reinstalation. I couldn't find a parts store with the right size puller. Thats where I spent hours looking for one and ended up at a mechanic that I know. You will not lose any Freon unless you disconnect the lines from the compressor. You will not have to disconnect those lines if you just do the clutch assembly. ;)