ANJU

hi, i have recently brought a 07 reg 220d however i have now noticed a rattle coming from under the car, when i dip the clutch the noise goes away? the transmission is still smooth and car picks up fine however the noise is obviously not supposed to be there i take it. i can also here a slight nocking noise also coming from the same place. i have been told it may be the dualmass flywheel and the clutch? can someone please advise