How long should one let the engine idle with cold?
Thread Starter
Junior Member
Joined: Oct 2014
Posts: 48
Likes: 0
E320CDI
How long should one let the engine idle with cold?
I have an E320CDI(should have the OM642 engine). How long should one let the engine idle with a cold(-5 Celsius/23 Fahrenheit or lower) weather? I have read that one should not let the modern cars with fuel injection sensors to idle at cold because the engine works in rich mode(more fuel is pumped into mixture) when cold and extra fuel works as a solvent for engine oil.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
I no longer live in such cold weather, but even when I did, I started driving immediately when engine would run with no hesitation.
On old carburated cars pushing gas pedal would kill cold engine, but being soft on clutch I could start rolling on 1st, than 2nd and by the time I was ready for 3rd the engine already warmed up enough.
On old carburated cars pushing gas pedal would kill cold engine, but being soft on clutch I could start rolling on 1st, than 2nd and by the time I was ready for 3rd the engine already warmed up enough.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,249
Likes: 257
From: Richmond, CA
2001 E320 Wagon, 2006 LBZ Silverado, 2007 E63 (sold), 2001 E55 (sold)
It doesn't get anywhere close to being that cold here, but I always drive off once the car drops down from the high idle. I take it easy until they're fully warmed up.
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,749
Likes: 881
From: In the Shadow of the Tetons
2013 ML350 Bluetec
Got the '05 CDI in my driveway. Temps range from 100F in the summer to -40F (rarely) in the winter. I sometimes start the car and let it warm, sometimes I start the car and drive. Depends on how much of a hurry I'm in. Either way, I don't worry about it BUT I don't drive it hard until I see at least one bar on the temp gauge.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,249
Likes: 257
From: Richmond, CA
2001 E320 Wagon, 2006 LBZ Silverado, 2007 E63 (sold), 2001 E55 (sold)
It's better to go by oil temp instead of the water temp. The water gets up to temp way before the oil on my E63. It shows to take it easy until the oil hits 80°, which usually takes 4-5 miles of driving.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
some years of SL class don't have coolant temp gauges, but oil temp gauges. Now $10 BT adapter can display that on your android.
Still there is long way from rolling a car with cold engine to racing it.
Still there is long way from rolling a car with cold engine to racing it.
