[kjames]

Just bought a 05.5 tdi. 169k miles. runs great. Noisy rattle at idle. sounds like pully??? any ideas.

 

[Seatman]

Can you tell where the noise is coming from? Is it coming from the auxillary belt area? and do you have a/c because I've seen the pulley on them make a racket when they're worn. Or tensioner for auxillary or alternator pulley. You could take off the auxillary belt and see if it goes away and if it does you can then check out all the pulleys etc while the belt's off.

 

[freerider]

Sometimes the clutched alternator pulley rattles. Is the tensinoer loose? Try to isolate the noise. If it's close to the transmission it could be a bad flywheel.

 

[DReams]

A rattle while idling can be a sign of a failing DMF (dual mass flywheel). It sounds like marbles in a can. Lots of info here on DMF failure.