My A3 2 litre TDI goes in for it's first service next week. It has a hesitation at 2400rpm on a changing throttle, it's not there when you drive through that engine speed on a constant throttle. It seems to have got worse recently, does anyone know what causes it and can it be sorted at the service ... or is it a case of they all do it? thanks Andy p.s. I did search first but couldn't find anything.