I've got an 51 (32K mls) plate 1.4 petrol and it's idling is odd. It seems to suffer when coasting from 1st gear the worst where the idle drops to nearly stalling point (~600 RPM) before pushing back up to normal ~700. This occurs when the engine is at normal operating temp and is seemingly unaffected by ambient temperature. Once idling, it is not enitrely solid at ~700 either.
Perhaps related is the fact that when the engine is up to normal temperatue and the car is at idle, using the electric windows or moving the power steering causes the revs to drop quite considerably.
I've has the odd occasion where the idle bounces from 600-800 rpm really quite rapidly and it seemingly is cured by a dab of the throttle.
I've just has a service with the 'additions' of plugs and filter and it has made no difference. Battery looks OK (green on the indicator of the battery) but is now 5 yrs old. These are expensive though so reluctant to replace until required. Audi told me the leads 'never' need replacing which I find odd.
So far the car has not stalled (touch wood) but is a concern. Car drives fine otherwise i.e. no misfire.
All notes taken when the AC compressor is switched off.
Any help will be greatly appreciated!