Well this is one damn sound I've never heard before. In any gear, at like 2500 rpm and over with any more than 1/4 throttle, there is this inconsistent raspy sound coming from under the hood. It almost sounds like a suspension sound, but it only happens when I give it throttle. Any ideas???

have u checked ur heat shields to make sure there not causing it.
try putting it in neutral with the ebrake up and pop the hood and rev it up when ur infront of it to see if u can hear where its coming from.

My car also makes a similar sound in the exact same conditions, I think it has to do with my belts though, after the raspy sound begins they start to squal like a mother! Pisses me off. When the car is in neutral though there is no wierd noise or squealing like that when I rev, it is only under torque involved driving conditions it sounds like swine. I also noticed on my first failed attempt at installing my AFX UDP, that the air conditioner pulley sounded a bit rough when I rotated it by hand a bit, WD-40?

I know this one. On my 98 auto I had that sound and insisted that the dealership fix it, they replaced both my inner and outer timing belt covers that they finally excepted as warranty work that cost $500, I got the car back and still had the noise. I brought it straight back and it ended up being the power steering pump (needed to be fix, aligned, replaced, dunno cause they didn't tell me). My 97 manual now has the same problem, but I haven't had a chance to take it to the dealer yet.

I have the same problem and me and my buddy checked it out and it kinda sounds like it is coming from the timing belt tensioner. I am about 10,000 miles past due for my timing belt replacement, so I just assumed that's what it is. But I don't have the $$$$$ to get it replaced.

i have the same problem. i notice it when i give it a little throttle about 2500 rpm, it stops around 4500 and then comes back at 5500 and up. I have re tightened everything under my hood and can not figure out what it is. I will second the "no problems when in nutrul only when in gear". It could be the power steering but i'm not sure, i'm on my third pump (first one the shaft came out, second the shaft seal went bad after 10 months and the third seams to be o.k. right now but you can hear it stress when i turn the steering wheel all the way). maybe when i take my car up to be dino'd i can listen and find it. until then i just put up with it, but it does suck. anyone who figures out this common noise i will give you 10 bucks and my respect.

Josh