I have recently bought a 2003 A4 Avant Quattro 1.8t and today whist being stuck in slow moving traffic i noticed it was idling a bit fast (1100 rpm).
Next it climbed up to 2000 rpm then dropped back down to 1000 rpm and stopped there for a few seconds then the process started again.
Can anyone shed any light on what could be causing this to happen please??
I know the car needs a new n75 valve as it has been backing off the boost for weeks and not sure if this might have something to do with the revving problem.
Many thanks in advance