I was cruising the 2000 c5 around today, driving it pretty hard, not powershifting but very fast throws. As I was slowing down, I still had it in gear and without the clutch down its starts making a noise like rocks in a bucket and then proceeds to do it while the clutch was down. At a stop I put it in neutral and let go of the clutch and it makes the noise right before I release my foot. I was like 1/2 mile from my house so I put it in first gear and slowly try to give it some gas, it goes forward a few feet then jerks back. I turn the car off and back on and then try to put it in second gear but it is stuck, like the clutch was not releasing the shifter. I am able after a few minutes to get it into second gear and drive home and it only makes a few rocky noises on the way home. When I come to a stop again it makes the rocky noise as I let go of the clutch with it in neutral. I turn the car off for a few minutes and then start it back up, it doesnt make any noises when I press and release the clutch several times, so I put it into first and drive it around the corner going thru the first four gears with no noises. But once again when I stop it makes the rocky noises when I release the clutch in neutral and this time not as bad as before.

Let me also say I just put in a new c6 z06 clutch, bearings and slave cylinder, as well as a used torque tube in December 2008. Before I replaced the torque tube it was making noises that were similar, only I could not drive at all.

Any help would be greatly appreciated.

 

SOUNDS LIKE PILOT SHAFT BEARING IN THE FLYWHEEL OR BAD CLUTCH INSTALL

 

That is what mine sounded like when pilot bearing went bad.

 

Jack it up and pull the inspection plate-if everything you can see looks and works ok,it definitely could be the pilot bearing-mine went out a short time ago,and it didn't make a whole lot of noise,but it was close to impossible to get into gear.
Don't let it go on too long,or it'll chew up the end of the propshaft.
I replaced the stock pilot bearing 2000 miles ago with a Kevlar bushing from Jegs-it's more tolerant of a less-than-perfect propshaft,and very forgiving of "alignment difficulties" during drivetrain reinstallation.
I've also heard good things about the oil impregnated bronze pilot bushing from others on the forum,and they're dirt cheap-just make sure it's solid bronze,not steel/bronze (it shouldn't stick to a magnet)

ALTHOUGH,in re-reading your post,you say it makes the noise when you release the clutch?
Do you mean foot off the clutch,in neutral?-if that's when you're hearing noise,it's not the pilot,sounds more like something in the torque tube.