lumpy tick over on audi 3.2 v6 dsg

[donna3.2]

on my 3.2 v6 2005 the tick over seems alittle aratic when cold , and not as bad when warm almost lumpy , it`s only done 51000 miles full service history, i would take it to audi but i brought it from ford as a part exchange, so it`s still under warranty from them, before i take it to them i would like to find out what it is , so they dont turn around and say it`s ok.:1zhelp:

thanks

i had a merc ml320 before and this is better quailty car by far.