odd noise
 

When im driving, at 3.6 rpms ( and only 3.6, nowhere else) i hear a buzzing sound. Like a dremel on a piece of metal, type sound... thats about all i know right now, just got in. Anyone have any clue what this might possibly be?

A dremel?

handheld electric tool, similar to a drill. used for hobby type purposes and other drilling, grinding and cutting tasks.

I think you may be exciting the natural frequency of something in the vehicle. Everything has a natural frequency. I have another vehicle that does it at about that speed. In my car (different brand) it is a piece of the fiberglass intake vibrating at its natural frequency and hitting the fiberglass fender liner. It is a sharp buzzing sound. A buzz because its frequency is high.

I had a similar question on another thread a while back. I had a similar vibration at just under 4k but without any noise. it seems that all 944s sooner or later develop a vibration around 3.5 to 4k. that's probably what's making something else in the car buzz. as Lawrence said, there is probably something that's not quite screwed down right making the noise.

Check the heat shield over the passenger engine mount. Has two small bolts that hold it on from the back side.

SoCal is probably on the right track. The heat shields back at the muffler or other components of the exhaust system (cat?) could be vibrating and resonating at that "frequency."