Ive just perchased a 2005 v6 3.0 asn a4 cab that the owner

Thanks for choosing Just Answer. I am here to look into your question today so please feel free to ask me anything required in order to get your problem resolved! We all understand it can be annoying when your auto is not operating as expected but not to worry I will do my upmost to help get it sorted. I am just looking at the information you have provided now so just bare with me for a few moments please.

Thank you so much for your patience today, I can see that you are having some difficulty with the belt contaminated with oil can I ask if the vehicle runs?

That is okay, as I am unable to take calls at this time it is just a suggestion you don't have to accept, do you know if there were any fault codes at all?

Hmm, do you know if the previous owner had it done himself or at a garage?

I am just trying to get a broader understanding of what was done and to what standard. so usually the seals leak just a little bit but not extensively and especially once they have been bedded in I would think that the timing case cover gasket. have you noticed any signs of coolant leaks or was it just water? or failed PCV causing the excess pressure blowing the gasket.

and yes, I have seen the PCV fail I usually get the uprated one as they usually last a lot longer on the audi's rather than them failing but they are reasonably common and it is usually on the driver's side just under the engine rocker cover so you will have to remove that.

and yes if the PCV has failed and over-pressurized the system then the seals would go due to the age of it, it isn't unusual to see.

I would replace them, as they are leaking meaning the seal has ultimately failed and they shouldn't go again after that unless the PCV or something else decides to fail as the seals themselves arent replaced with timing or schedule. when they fail they fail.