my old clutch had been making a sound similar to what you are describing. it made like a chattering sound at idle. my clutch had went out like a year later at around 85,000 miles(stock clutch). the springs were all loose in the disk and one spring had came out and got stuck in a release arm on the preasure plate. driving with it like that was mostly a pain at stop lights. it didnt want to go into 1st from nuetral with the engien running.
