I just dropped my gf off at school and the car was fine until I came to a stop at a turning lane about 1.5 miles later. The noise sounds like grinding/squeaking coming from under the hood as I let off the clutch while in first gear. It'll go away as I accelerate, but I hear the noise slightly in-between shifting. It's fine when idling, but it's also pretty bad when reversing, as it was embarrassing to back out of a parking space and have a whole bunch of people look over at me.

Anyway, the car is a 2005 2.5RS w/ 102,xxx mi and mods under the hood are: perrin lightweight pully and injen intake. I took a look at the belts and none of them seem to be loose or anything. Any ideas?