Ok first off this is a b5 1.8t. The car has 128k on it. I was just driving along and suddenly a vibration in the clutch pedal when I depress the clutch to up shift. Also when I take off from a stop there is a chattering noise. While driving it seems fine. I do notice a slight noise at lower rpms like when im slowing down to come to a stop while in gear. I was thinking a bad throw out bearing but then I noticed while clutch pedal to the floor i can gas it and it will make 1 chatter and then nothing. Any input would be greatly appreciated.

 

Sounds like it could be a bad dual mass flywheel since you only have the issue when there is no or very little load on the flywheel/clutch.