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Discussion Starter #1 (Edited)
Hi
I have noticed since the start of Winter "8 to 16 degrees C" that my car has a much more noticeable idle, I normally do not warm up the car, I just wait for like half a minute or less until the RPM falls under 1 to 0.8 and drive.
Should I warm up my car in general to avoid rough idle ? Should I have my car checked ? In general the rough idle is felt through my feat while on the break pedal. It is a rhythmic rougher shake every few seconds and smaller closer to normal vibrations in between. I can feel it more noticeably when I turn on the heat AC.
Please advice

Note : RPM stays stable during this.
 

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as long as your rpm needle is steady at 500 rpm in drive at a stop...u have no problems

waiting 30 seconds is fine...at that temperature u can wait a minute more to get the oil pressure up

their is a valve that stays closed until a few minutes have pasted....thats probally why it feels rough

as long as u have no check engine light

wat car do u have? year model miles?

call your dealership and give them your vin to check for recalls that havent been done
 

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Benz are dead against static warm up - it is every handbook

The mixture is very rich at startup to enable drive off - the best thing you can do during this period of a cold motor is to drive at moderate revs to counter the rich mixture.

Oberoi
 

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Hi Oberoi
Can you explain that a little bit more please ?
Regards
It's my understanding that idling with a very rich mixture (or idling for long periods for that matter) is detrimental to bore lubrication

The higher oil pressure when you get over 1000-1200 rpm overcomes this. In addition the unburnt rich mixture in a cold engine can wash or dilute some of the oil in the bores.

Higher revs would lean out the mixture a bit as the engine has enough inertia to continue running without such a high fuel ratio.

The Benz handbooks mention the undesirability of both idling(hot) and cold warm up
That said, we don't have to put up with the extreme winters here so I will admit to not having first hand knowledge of having to start off below zero.

Oberoi
 
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