Hi Rallyboygower

I had chain rattle on mine... an A6 Avant 3.0 TDi occurred at about 73-75K on clock... my symptoms where only at start up for 1-2 seconds...

I've just had fix for all chains & tensioners, HPFP belt & tensioner, AUX belt & tensioners, Tiptronic oil change as well price was £2.2K inc VAT

As engine is removed they did a oil change, coolant change, re-gas of A/C system

These are P/N and supersession history

057 109 218 G DROPPED 01/10/2005
057 109 218 J DROPPED 01/12/2006
057 109 218 K CURRENT

Even though my car first registration was 09/2005 many parts have production dates of 6-7 months before that
So going only by my personal experience I think your car qualify having suspect tensioner
My advice and as you can tell from others posts in thread get checked and done

£2K is big bill but if you take out full service cost which you getting then £1500-£1700 is not bad price for amount of work...

My photo album link:- My A6 Chain Stuff pictures by gupsterg - Photobucket



On above photo note the shape of right top bank chain lower end of it....