Bear with me as I am doing my best to learn here. So basically- off and on for the past month or so -(but increasingly so) my kia has been making a very loud squealing sound whenever the ac is on (it would immediately stop as soon as the ac was turned off, no delay). I know I shouldn’t have ignored it for so long- but now the ac has stopped working, no more squealing. Is this likely the serpentine belt or a pulley or something else? I will be taking it to the shop in the next few days- I just wanted to be a bit more informed beforehand. Thanks for any help!
I guess your squealing problem is solved.
Turn the engine on, turn the a/c on full blast and observe the a/c clutch in front of the pulley. Does it turn in tandem with the a/c pulley? If yes I imagine your compressor is dead, broken shaft or some other internal organ failure. If the clutch does not turn you may have a bad clutch and somewhat lucky because that would not be too expensive to fix. The noise you heard very likely was as a result of failed clutch or compressor causing the belt to slip over the a/c pulley.
What year is your Rio and how many miles on it?
It is a 2006 and almost 80,000
If it were the serp belt or the tensioner, the engine would be dead now, unless on this engine the AC compressor uses a dedicated belt. Some engines do because the AC compressor places so much load on the belt.
Try removing the AC compressor belt and turning the compressor pulley by hand, and checking it for lateral and axial play (side-to-side and in & out). If it has play, the compressor clutch shaft bearing is shot. I don’t know if on this engine you can replace the cutch assembly separately from the compressor itself, but I’m sure you can find that information easily by looking up the parts… which you’ll need to do anyway.
Post back with the results of your checks.