Sounds like the bearings on your idler pulley or another pulley ate it.
https://www.nicoclub.com/service-man...14-SR20DET.pdf
MA-12 page for setting proper belt tension. What I'd do if it were me would be to remove the serpentine belts and try to spin the idler pulley and other pulleys by hand. Youll find out in short order which one needs replacing.