A6 C6 4.2 engine versions
 

Am currently wanting to buy a 2005/6 V8 but have found (here in England anyway) that the model was launched with the earlier 335bhp engine (5 valves per cylinder?) but was replaced by the later 4 valves per cylinder FSI engine just one year later.

I know there are carbon build up issues on the latter and possible timing chain tensioner issues but taking into account the age of these now I wanted to know which might be the better choice of engine for my purchase.

Any advice much appreciated.

I do like the feel/power of the FSI V8 much better than the older V8 version. However the earlier generation has less issues and has a slightly better sound to it in my personal opinion :)

Both are non the less great engines - I would grab which ever is in the better car.

Thanks for that advice - very useful in helping me with my decision.

So, after due consideration of all the additional electronics issues on later cars (as pointed out by my son-in-law who works as an AA patrolman these days and sees stuff like that all the time on modern cars), I decided to go for an earlier model of the S6 (2002) and am now very happy and confident that I've made the right decision for various reasons. And the power is more than enough on this engine :D