W211 E270 small negative temperature idle fluctuation

[mike75]

Hello . I have a W211 E270 2003 and when temperatures are negative as soon as I start the car i have a fluctuation at idle for about 10 seconds. It`s not a big fluctuation.... between 800 and 820 rpm after which it stabilizes at 800 and when it warms fixed drops to 780 . Do you think it`s a problem?

Also the engine noise ( that old diesel ) is present at negative temperatures .

PS Scan STAR and absolutely no error on the car

 

[Troon]

By "negative temperature" I assume you mean below 0°C?

Doesn't sound like a problem to me: lots of extra loads on the car when it's cold, such as the huge electrical heaters in the HVAC system.

 

[mike75]

Yes. Ex. this morning was about -2 C. The rest of the starts in the same day is without problem. Even the car sits more then 6 h.