I went away for a few days last weekend and left my car parked in our driveway, which has a pretty steep incline. Got in Tuesday to go to work and when I started it there were no problems. When I started it up to go home at the end of the day, this hideous whirring sound came from the engine. I immediately stopped it and opened the hood. Nothing seemed amiss, so I started it back up again; no sounds. Drove it home and parked it. Wednesday going to and from work I didn't notice any sounds. Then this morning I started it up and the sound was there. I popped the hood and I could pinpoint the sound to the left side of the engine before it went away. Right before I shut off the car at the end of my commute I could faintly hear the noise once again.
My first guess would be the power steering pump, since that's where the noise seemed like it was coming from. I should also point out that the water pump went a few weeks ago and the car overheated for a short time, but there supposedly was no damage according to the shop. Any ideas?
