Residue oil found on engine

[Bournebb]

I know very little about Audi's but almost bought an A4 Quattro 2.0 tdi but spotted dark marks of which is oil on the engine below the oil tank. I could smell oil burning after I got out of the car after a test drive and I'm just hoping for some advice and wether or not this is normal? It put me off buying it there and then but I'm considering returning with an aa inspector. Any views would be great
Thank you

[Rob69]

Hi, you don't say what year the car is, but I'd be more wary of the oil pump and balancer issues in certain years of the 2 litre than a oil drip. Do some research into this and you might rethink. I've had 1.9's in preference to the 2 litre.