Have noticed lately that my MY11 Superb 118TSI is starting to get a bit unsettled at idle. Rather than maintaining a steady RPM, the engine seems to fluctuate a little between 800-1000 RPM. This happens both when the engine is cold or at temp, but does not occur consistently. Sometimes it happens and sometimes not.

Car is at approx 75000 kms, and was last serviced 5000 kms ago. idle fluctuations happened both before and after the service.

Has anyone else experienced this or know the likely cause?