Whirring sound (on and off) drvers side.

Once in a while I'm getting a "whirrrrring" sound from the drivers side I think. I popped the hood, it was noticable. Pumped the gas and it went away. Only happened a few times so far. Can't pinpoint it just yet. I'm driving out in the middle of nowhere so it's sort of important to sort out. It's a normal sound, but like on steroids when it happens. High pitch whiirrrrr. Anyone ever have this?

 

I get the sound when I first back out of my driveway, but it's the abs pump. Pretty sure it does it every time I start the truck and begin to move.

 

It actually responds to the throttle sometimes. Louder when I put on the gas. I don't think I have ABS.

 

Sounds like a pulley bearing or tensioner bearing. Or power steering pump.