Adjusting engine idle speed

[Nudist]

I have a 2010 polo sports. The engine is currently idling @600 rpm and is rattling a bit. Want to increase it to 800 rpm . Does anyone know how to increase the speed please. The last time I did this was on a naturally aspirated engine and it was a simple screw adjustment

[brad]

You can do it via VCDS but if it's rattling I'd be inclined to get it checked over.

ECU controlled engines generally don't need adjustment to idle speed as the ECU "requests" a speed and various parameters are changed to provide it. If you've dropped to 600 then there's probably something wrong

[Nudist]

We had it into the garage few days ago for a regular service, Rattling of the chassis - my mistake not the engine - is more a case of low speed harmonics . I know my old 1974 Corolla used to rattle at low speed

[brad]

Was the idle low before the service? If not I'd be wondering what viscosity of oil they'd put in

[Nudist]

The car was last serviced with a VW dealer in Melbourne in August last year . So I'm confident it had the right grade of motor oil it has been idling slowly since I picked up the car two weeks ago . I took the car to my local mechanic last week and neglected to ask him to look at the idling problem. I am confident he used right grade of oil. I thought maybe I need to confirm that he did run a proper diagnostic over the engine ? Does that seem reasonable to you?