I had the exact same thing happen to mine. Turns out it was the AC pulley bearing. There’s a write up on here somewhere for the replacement. It’s not hard (and dirt cheap) but requires a press.
Edit: the writeup is on youtube actually:
https://www.youtube.com/watch?v=5qd0e-vVxQA
You will need Santech MT2031 bearing purchased at Autozone for $15. I did all of the work from above and used the recommended snap ring pliers in the video.
This is all assuming you have a 4.8.