Hey guys,

Have noticed for while now that when the engine is cold the car has a really 'lumpy' idle. The revs do not increase/drop at all but the car shakes quite violently.

This only seems to happen when cold, and when i turned the climate control off using the fan speed selector it seemd to go away.

This never used to happen unitl i had the cambelt changed and not ive got this issue.

Does anybody know what it could be, whether it is something serious that needs sorting ASAP.

Any help would be appreciated

Hey guys,

Have noticed for while now that when the engine is cold the car has a really 'lumpy' idle. The revs do not increase/drop at all but the car shakes quite violently.

This only seems to happen when cold, and when i turned the climate control off using the fan speed selector it seemd to go away.

This never used to happen unitl i had the cambelt changed and not ive got this issue.

Does anybody know what it could be, whether it is something serious that needs sorting ASAP.

Any help would be appreciated

I am assuming that the actual AirCon is also active. In this case when you drop the fan to 0 the air-conditioning unit turns off automatically, which means it disengages from the engine drive.

So I suspect it is just the extra load of the compressor when on cold idle making it a bit lumpy, so could point to a bit of wear on the compressor adding a bit more friction, or the belt to it a bit tight (not sure how it is driven in a VAG engine).

So, I would check with them, they may have tightened a belt a little too much whilst they were in there.

On my last car I could tell at idle when the compressor was switching on and off on its cooling cycles by the rev counter blipping a little more unevenly on idle. Car was 9 years old, and as I recall didn't do it when new, so as I say may be just a result of general wear over time. The aircon was still fine, but didn't want to investigate too much in case it was a new compressor!

Just seems really weird that it suddenly happened after a cam belt change from a supposed specialist.

I've tried two specialists now and something is always weird once the car cones back