u/Kadenpolo18

Hello I recently have this high pitched noise happening under little to much rpms it usually happens after the car is warm i have just replaced the idler pulley, tensioner, and both the ac belt and serpentine belt. Not sure what would be making this noise but it’s been happening last few months. No lights on dash or change in performance that I can tell just really loud and annoying. Any input would be greatly appreciated as I have taken to a mechanic already for the diagnosis which he recommended the parts I just replaced. It’s a 2011 ford mustang gt 5.0 v8.