Ever since the last service (full service + cambelt) was done, my VRS had this slightly lumpy idle before the engine got warm, then it would idle fine.

I Checked the timing syncro angle with VAGCOM to make sure the belt had been tensioned correctly, all was good. I thought the lumpy idle would go away once the belt had settled in. 1000 miles later, still lumpy.

Put my thinking cap on, garage changed the air filter (I use Mahne Air Filters), they had fitted a VAG air filter. Put the Mahne air filter back in, bingo, smooth as silk.

Interesting - my PD100's had a lumpy idle for a while now that probably also started around service time... I put it down to the pikey resistor mod I have fitted but maybe a change of filter may be in order!

Interesting - my PD100's had a lumpy idle for a while now that probably also started around service time... I put it down to the pikey resistor mod I have fitted but maybe a change of filter may be in order!

Try a Mahne filter, dogs danglies, and cheap as well.