Hi i need help identifying this part on my BKD tdi. some times when the engine is idling it rattles so i need to know if i should get it replaced or not worry about it.

its the part directly to the rear of the Aux belt

 

i recenlty had a new cam belt and auxillary belt fitted and wonder if this part should have been done too.

 

help as always is appreciated.

 

 

Edited 2 November, 20169 yr by mroberts

I believe that's the Aux belt tensioner but I would check the alternator pulley before replacing the tensioner.  If it's seized up then it will make the tensioner work overtime.  Google 'VW alternator clutch' or 'VW alternator pulley'.  Just had my pulley replaced as it caused the belt to squeak as well as make the tensioner rattle about.  Cost ~£46 for the pulley but no labour as it was done during the timing belt and aux belt change.

Edited 2 November, 20169 yr by andy-fisher

sounds like i should have been told about this when i had the cam belt and aux belt changed. might have to give th edealer a call see what he says and why it wasnt mentioned.

 

its definitely that unit as i can feel it vibrate.