So for the past week I’ve been having this obnoxious squealing noise coming from my engine bay at certain times. The first time I’ve heard it I went straight to checking all my belts but they were fine. I don’t have a vacuum leak so it can’t be that. The noise only occurs when going uphill or when in higher gears 3-4. My car is automatic so I’m 100% sure it ain’t the clutch.

 

Could try changing the hvac settings when it happens. Turn AC on/off and see if that alters it.
Maybe check fans too.