Not sure what do you mean by B8 ?
On a6 c6 Yes . The 2004-2006 BMK 3.0tdi has these problems
In 2006 they relised a revised unit ABS 3.0tdi they they improved injestors and injectors. And the 2009 facelifted engine was even better
Chain wasnt the issue , top tensioners it what the problem is .
But the "chain" is a problem in all audis... 3.2 and 4.2 petrol had issues .
Ive been reading on forums that 2011-2013 audis had issues with the chain as well...