not really sure if its a bad throwout bearing or not......i swear i have bad luck when it comes to showing off.....last night it rained i had the car out for a change and decided to mess around in a parking lot did a couple quick doughnuts and left when i was pulling out of the parking lot i noticed a humming sound almost sounded like i had a root supercharger on the car....only does it in 1st and 2nd and when the car is not in gear and i rev it a tad say around 2000rpm....i was thinking at first power steering pump i got home checked the fluid that was very hot and just a tad bit low so i filled it up maybe a 1/4 inch total and went for a drive still making the noise so i parked it and have yet to drive it.....talking to a few guys at work (i work at a dealership) they seem to think its the throwout bearing....i had 1 go up under warranty back at 17k now im at 53k its a 2000 camaro SS simple bolt ons LT headers, intake and loudmouth...part of the problem i cant tell if the sound goes away after about 3500 or if i just cant hear it over the exhaust....any help you guys can give is greatly appreciated....thanks in advance