W212 idle rpm

[tylerdurden]

Normally it will idle at 500-600. Out of the blue will idle at 800-900. I understand it's something to do with renewing the DPF.

However with the cold weather it's idling at 800-900 most of the time, even with a nice warm engine. Seems a great waste of fuel and notvery green. Is there a good reason for this?

 

[mbenz76]

Mine does exactly the same and like you I have been told it's the DPF so no longer worry about it.

In the cold it idles at 800-900 until the engine temperature gets to normal (just over 80 degrees), then it drops back down to 500-600 every time without fail. No idea why this is but agree it seems odd.

 

[Aoraki]

Hmmmm mine did that and MB updated ECU software to cure the problem, which it did. No metion of DPF.

 

[mbenz76]

I am due the update to fix the diesel clatter but had to postpone for a couple of weeks due to the weather.