Bouncy idle

[Fourth BMW]

Hi, I have recently purchased a 2018 BMW 218i although the idle is a bit random, when I put the clutch down to coast to a roundabout/junction, the Rev counter will shoot up to between 2.5 and 3 revs, then come back down again, it doesn’t do it all the time, it has been into bmw and they changed the tank vent valve, which has made no difference, any suggestions?

[Initforthemoney]

Take it back again?

[Fourth BMW]

It is booked back in, although I don’t think they know what it is, I thought I would pull on the knowledge of the experts on here to make some suggestions when I drop it back off.

[AndyXF]

Is it the car attempting auto rev-matching? If it has such a feature.

[Fourth BMW]

I have never heard of Rev matching but I have just googled and watched some videos and it looks exactly like what is happening, the videos I watched though were showing you how to do it manually, can the car have an auto rev matching feature?

[JaredVannett]

Isn't the rev matching a feature on newer ///M cars only?

[Fourth BMW]

It has all the m livery on it along with the m steering wheel and gear knob, I assume it has it!

[AndyXF]

Fourth BMW said:

I have never heard of Rev matching but I have just googled and watched some videos and it looks exactly like what is happening, the videos I watched though were showing you how to do it manually, can the car have an auto rev matching feature?

I believe when the clutch is dipped and as you move towards a new gear, it will rev to a certain rpm that’s suitable for that gear.

[Fourth BMW]

Thanks all, this has put my mind at rest, is there a way to turn rev matching off?

[AndyXF]

Fourth BMW said:

Thanks all, this has put my mind at rest, is there a way to turn rev matching off?

Unfortunately I’ve no idea about BMWs, it was just a guess! You might have to sit and read through the manual