I have an 06 EVO IX GSR with roughly 9000 miles on the odometer, bone stock. I've noticed over the last few days there is this noise coming from under the hood when I start to accelerate from a stop. The noise is prominent until the engine has load or until I start getting up in speed. So I experimented this morning, and tried reving the engine lightly at a stop, and the noise comes and fades with the rpms. At Idle, I hear nothing. On light reving I can hear it prominently from the passenger side. I popped the hood at work today and pulled on the throttle cable a little and it sounds like it's coming from the passenger side, inside the valve casing, or at least in close proximity. What's odd is I only hear it at lower speeds, once I'm up to full speed it's gone. Reving while at higher speeds does not reproduce the noise. It isn't dependent on the transmission being engaged. It is definitely coming from the engine area, and sounds equivalent to loose coins jingling in your pocket, or very very faint brake squeal (best analogy I could come up with). It doesn't seem to affect the driveability of the car, at this point. But it is concerning. I'm due for an oil change next week at the dealership. They will be looking at the car, but if anyone has any ideas what this is, I'd love to know.