Audi related question

[printeral]

Hi All,
I`m asking this question on behalf of my bruv.
I know it`s not VW as such but wondered if there are any peeps out there that could help,or at least point him in the right direction.
His car details are:
Reg: YY05 ***
Audi A6 estate SE CVT
Engine: 2.4 v6 petrol
Multitronic
This is the engine that has 4 timing chains at the rear and no timing belt !!!(apparently)
Problem was sound of chain at top rear of engine....maybe cam timing chain tensioner problem???
He`s been told that this can be changed without dropping engine but the only people that he can get interested (Audi/VW dealerships) say 3k-4k because engine has to be dropped
My moby is 07803 142922 or mail me if any of you can possibly help him at all.
Thanks for looking

Printeral