[1999 White C5 Coupe]

First try at the fix the mechanic said it's the AC compressor.
So he replaced it with a by pass pulley, a wheel connected to nothing look like.
Did not work.
Noise comes and goes intermittently for short periods, maybe less frequent than just before the fix, but still very load.

He was rude and i would prefer to go to a new mechanic.
I don't know know if i can go back and get further work free.
I am wondering about the risks of driving short distances over the holidays until a mechanic is free next week.
any insight into causes and fixes appreciated.

thanks.

It would be helpful to post the year, make, model, trim line and engine.

 

[1999 White C5 Coupe]

Thanks, duh! lol

The idler pulley(s) and belt tensioner pulleys often wear and cause continuous or intermittent squealing. They are wear items and cannot be repaired.

I would replace the serpentine belt and the pulleys (held on with 15mm bolts), and use OEM ACDelco units. They are inexpensive and high quality (vs poor quality aftermarket).

When you remove the idler pulley(s) and belt tensioner pulley, look on the back side - you will often see where the grease has leaked from the sealed unit, causing metal wear and the sounds you hear.

The sounds are very difficult to isolate to one pulley, especially if they are all about the same age. After belt removal, you may find one or more of them are “wobbly” - but look and feel tight when the belt is attached.