Irregular (unregelmäßig) idle speed

[René Hazejager]

Hi Collegues,

My Plussie starts to run fast-slow-fast when I go down hill e.g. into a parking garage. The revs are between 500-1100 rpm every second orso. Very irritating. It stops when the car is back in horizontal position.

Has anyone a clue?

Thanks.
René.

[Marc Welsch]

I have to ask for some details about this situation. You are driving downhill in the first or second geear and using your brake?

If that is part of it, it's completly normal. If you are going downhill in the second gear with less than 10km/h you will have less than 800 rpm, because the gearbox will slow down the engine. But 800 rpm is the minimum of the engine, the electronic trys to hold the 800 rpm and pushs up the rpm-minimum-limiter, to get more power.

The new limit is at 1'100 rpm. It needs some time, untill the electronic goes back to the standard-situation, sometimes about 30 seconds!

[René Hazejager]

Marc,

The gear in it's neutral and I'm braking. The engine should rev as normal, but it moves up and down. Have my foot NOT on the throttle pedal, only the brake is active.

Thanks.
René.

[Sebastian]

Sometimes i have the same problem and i think, you must clean your "Leerlaufregler" with break-cleaner.

[Rainer Langer]

Hi together,
i had the same effect with my s6.
it is not special for your "garage way" but i had exacly the same effects...

im my case, the engine gets wrong air. The air filter did´nt fit exactly.
Look at your screws and at the tube. It is also possible that there is an small hairline.

/Rainer

[René Hazejager]

Collegues,

I checked the airfilter box, tubing and I pushed/pulled the various devices in order to create the problem. All seem to be 100%.

Left: 'Leerlaufregler', as Sebastian recommended to clean. Can someone tell me what this device looks like and what I have to remove to access it?

Thank you.
René.

[Sebastian]

You must remove the motor-cover and above the gas-wire and the cruise control you see an silver cylinder - that is the idle-controller.

Only three nuts you must undo and than you can clean ist...easy work