I have a 2007 2.0 tfsi convertible. It has a regular misfire on tickover but runs fine when driving. A full service by a good mechanic (so I can rely on him) reduced it slightly but it is still there. Does anyone know what could cause this?

Hi Nick...welcome to the Forum

I would run a scan on the engine management system to see if there are any fault codes logged for the misfire.

If not, then it could be virtually anything, even the quality of the engine oil or vacuum leaks....best to test the individual systems before replacing any components though.

Keep us informed on how you get on with this

Cheers  Trevor

Hi Trevor,

Thanks for the welcome. Interestingly I had a good listen to the engine and the mis fire seems to coincide with a very quiet regular venting noise from around the rocker cover. I am more of a m/cycle person so forgive my possible stupidity when it comes to audi engines but it there some type of crank breather valve?

A modern engine should not vent to atmosphere but the venting noise could be an air pump/valve or even acoustic valves in the inlet manifold, but it may be worth checking it with a specialist Audi repairer to ensure it is not doing any damage to the engine.

What motorcycle(s) do you have?