About two weeks ago I started noticing an odd noise coming from under. It sounded like a very faint electric razor sound. The volume is slow increasing over time. It happen only when the car is first started, while driving and at idle and last for the first few minutes.

I popped the hood the other day when I heard it and it's coming from the driver's side where the belt is located. Tending to rule out the SC tension pulley b/c that's on the passenger side (had that issue before and it's a totally different sound).