Bad AC pulley/bearing causing noise when applying throttle in gear?

[kensansai]

There is a rattling noise when I spin the AC compressor pulley. Seems like I need to replace the pulley or bearing?

There's also a tapping noise from the engine bay when I apply throttle and hold the brakes in drive or reverse (but not in park). It's shown in second half of the the video. This noise also occurs when accelerating from stand still. Could this coming from the bad AC pulley or bearing?

Car is a 2010 XC70 3.2 I6 with 140K miles. Engine and transmission mounts have just been replaced this week. Idler pulley and tensioner replaced 20K miles and 4 years ago. The crankshaft, water pump, and power steering pulleys haven't been replaced but they dont make any noise when I spin them.

Thanks!

[scot850]

Sorry. did not see this 2nd video and update. I would link the 2 threads so that you get all the info out in one go.

If the A/C clutch is rattling like that it could be it has failed. Again you need someone physically to get their hands on it to confirm.

Neil.

[kensansai]

@Neil Thanks! Sorry I couldn't figure out how to remove or link the previous post.

I took the drive belt off, started the car, and tried to reproduce the noise. Car runs smooth and I can't reproduce the noise with the belt off.

The coolant pump, idler pulley, tensioner, coolant & power steering pulley, and drive pulley don't have any play. I will be putting on a new water pump and drive pulley since I already took everything apart.

I actually took off the A/C clutch and found out where the noise is coming from. There is grey band of (I think its some sort of metal) material on the pulley pointed to by the red arrow in the photo. It has completely disintegrated. There's a loose broken piece between the pulley and clutch which causes the noise.

I also noticed the compressor shaft was slightly wet with green fluid. So it looks like the A/C shaft seal has a very slow leak. I'll be getting a UV flashlight in the mail tomorrow so I can see the extent of the leak. I'm also removing a shim when reinstalling the clutch since the clutch gap is too large.

I'll re-install everything once I get time in the next few days. If the noise is still there, I'll try to isolate whether it's the A/C. And if I can't figure it out, I'll take it to a shop. I might have to take it to a shop anyways if I need to install a new compressor cause I don't know how to deal with the refrigerant.

[kensansai]

Just giving an update.

I removed the loose piece from the broken grey band in the pulley.

I also replaced the READ drive pulley and water pump since I already spent time taking everything apart. The pulley wasn't able to free-wheel. I thought that's how it's supposed to be until I put on the new one and the noticed the new one free-wheels. So I guess the old one was seized.

Now the noise is gone.