2006 s3 hunting/eratic idle?

Hi guys (and girls)

I have had my s3 for a few months now, and on sunday night it developed a rather odd idle...

The car sits below 1000rpm and the needle is moving very quickly between 600 and 900rpm.

The car also hangs on to the revs and occasionaly sits at 3k revs for a few seconds before it goes back to its funny idle.

When driving the car and throttling off, you can feel the car hesitate to drop the revs, and eventualy they fall, but feels rather "jerky"

I have no engine warning lights on as yet.

I have checked for any air leaks/Vac leaks, and cant seem to find any.

briefly on monday afternoon it calmed down and the revs sat at a steady 1100rpm, i then switched on the air con and it brought the revs down to 800ish rpm and it was better.

Any help would be great.

Thanks, Louis

jungleman said:

how old are your spark plugs?

Click to expand...

Car has 35k on the clock, looking through service history, there is no evidence of them being changed.