In each of the last few mornings, with the first start of the day, I am hearing a noise that sounds like a bearing on something might be going bad. The sound is a combination of a rumble/squeal/screech. As the car warms up and is driven, the sound will go away. We are in Phoenix, so the AC is on right now. Yesterday, at the morning start-up, I was hearing the noise. I shut off the AC to see if that would stop the noise, and it did not. So I hope that might mean that the AC compressor is not the likely suspect for a bad bearing.

What are some of the other pulleys that ride on bearings that might be failing at the age and mileage of my vehicle (2000 with 105,000 miles)?

Does the Q have idler pulleys? Could it be the water pump (not seeing any coolant leaks, however)? Other ideas?

you have 4 belts.
and, lucky you you also have 4 idlers.

Given my mileage, should I just change all 4 of them since it might be hard to identify which one is going bad?

Check that. I just checked some prices. The pulleys don't look cheap. Any tricks or tips for diagnosing which pulley might be the one that is going bad?

Here are some methods I have used

1. Doing your best to avoid the belt and the fan, place a long, hard object against the bolt in the center of the pulley while the engine is running.
2. Remove the belt and spin the pulleys by hand. If it's bad enough to be audible from the cabin, it's likely that you'll hear it that way too.
3. (I don't know the layout of the 2000 Q belts, but 4 is a lot). Depending on how the important accessories are driven, I have also removed belts individually and started the car to see which one results in silence.

I might be wrong in this, but testing by engaging the A/C will usually help you catch a clutch issue. Otherwise the comoressor pulley bearing is always turning.

Thanks for the ideas on the pulleys. I have been reading some more and watching some youtubes. Before I try the pulley tests I am going to make sure my problem is not as simple as a contaminated belt. A valve cover gasket job along with changing the oil pressure sending unit a few months ago stopped up almost all of my oil leaks. I still have a small, infrequent drip that seems to be coming from the front of the engine, maybe the timing cover area. I have been cleaning the area to try to locate the final oil leak. I think I may have smudged some grime on one or more of the belts. I will buy some belt conditioner and spray the belts down to see if that solves the problem before I start down the path of checking the pulleys.

My 1999 has been doing same thing and it's my air conditioner compressor couch bearing making the outside plate spin

My buddy at a local shop has my Q and he says he thinks the noise I am hearing is from the idler pulleys for the power steering and alternator. Doing research on this site, I see that folks are replacing the bearings on those pulleys instead of replacing the entire pulley. The shop can order the pulleys but the dealership wants $100 for each pulley. The bearings for the Gen 1 cars were said to be 6301 type. Is that also the correct bearing for the Gen 2 Y33 cars? Has anybody else had success replacing the bearings on the Y33 idler pulleys or am I stuck paying the price for the pulleys?

Never on the idle pulley I have just replaced them but I have on the a/c compressor bearing it has worked out pretty well so far