A6 4.2 V8 (BAT) non-FSI: timing chain issues?

[RoVoFob]

I’m looking at large, big-engined petrol estates and a 4.2 V8 A6 Avant has popped up. This is a 2005 model with a pre-FSI BAT engine.

Can anyone tell me whether these have costly issues with the timing chain guides and tensioners like the older models do?

I long considered an S4 Avant (B7), but was scared off by the likelihood of big bills, but don’t know whether this version of the A6 is similarly afflicted.

If anyone can enlighten me I’d be very grateful. I’ve done a number of searches but can’t work out where this version of the A6 comes in...

Thanks!