How long to "warm up"??
01-04-2012, 12:37 PM
#1
Member
Thread Starter
How long to "warm up"??
We all know that cars run less efficiently when below their thermostated temperature.
This is my first winter with my ML350 and it seems to take a long time to get up to temperature. I'd like to be sure that there isn't an issue with a thermostat stuck in bypass or something.
For example, this morning it took 10 minutes to get to 80C at 50 mph. The outside temperature was -10C (13F). It seemed like a long time (to me) based on my non-MB cars. It does get to 90C, but it takes f-o-r-ever.
What's your experience? How can I tell if I've got "a problem"?
This is my first winter with my ML350 and it seems to take a long time to get up to temperature. I'd like to be sure that there isn't an issue with a thermostat stuck in bypass or something.
For example, this morning it took 10 minutes to get to 80C at 50 mph. The outside temperature was -10C (13F). It seemed like a long time (to me) based on my non-MB cars. It does get to 90C, but it takes f-o-r-ever.
What's your experience? How can I tell if I've got "a problem"?
01-04-2012, 01:32 PM
#2
Senior Member
10 minutes doesn't sound too bad to me for an outside temperature of -10. However, I have a 550 so I'm not sure it is the same.
But the point I want to make: It is the oil that has to be up to temperature before you start honking on the gas pedal. On my wife's M3 -- the only vehicle we have with both a coolant and an oil temperature gauge -- the oil takes just about twice as long as the coolant to reach operating temperature, so I use this as a guide for my other vehicles as well.
But the point I want to make: It is the oil that has to be up to temperature before you start honking on the gas pedal. On my wife's M3 -- the only vehicle we have with both a coolant and an oil temperature gauge -- the oil takes just about twice as long as the coolant to reach operating temperature, so I use this as a guide for my other vehicles as well.
01-04-2012, 08:37 PM
#3
If your thermostat was indeed stuck open you would never reach 80 deg C (176 deg F) while driving 50 mph in 13 deg F weather...
In fact you might not even reach 38 deg C (approx 100 deg F) in those conditions after hours of driving. How would I know? Because I had this occur on a trip from between Syracuse to Albany and back (a non-ML350 but a MB vehicle; the principle remains the same).
As to comparing the rate that a vehicle warms up with other vehicles... get yourself an air-cooled VW and find out what "forever" is like to get a vehicle to heat up... let alone reach a comfortable temperature in 13 deg F weather!
In fact you might not even reach 38 deg C (approx 100 deg F) in those conditions after hours of driving. How would I know? Because I had this occur on a trip from between Syracuse to Albany and back (a non-ML350 but a MB vehicle; the principle remains the same).
As to comparing the rate that a vehicle warms up with other vehicles... get yourself an air-cooled VW and find out what "forever" is like to get a vehicle to heat up... let alone reach a comfortable temperature in 13 deg F weather!
01-04-2012, 09:19 PM
#4
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Join Date: Sep 2005
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2007 E63
The coolant temp gauges on Mercedes are actually more accurate than others. On a lot of other vehicles, it's either at cold, dead center, or overheating. The gauges on the ML fluctuate properly with the actual coolant temp. I wouldn't be too worried.
01-05-2012, 06:54 AM
#5
Member
Thread Starter
Thanks for the input/feedback!
I have not only the "dashboard" gauge, but also an OBD II gauge monitoring system. I realized yesterday that the two gauges don't line up and that the OBD II gauge "lags" the "dashboard" on warm-up by 5-10C and then overshoots it ending up around 96-97C. (The "dashboard" stops at 91C or so.) I suspect that the two guauges get their inputs from different places.
Coming home yesterday I hit 80C (on the dash) at 7 minutes at -2C (30F), so it was much faster.
I have not only the "dashboard" gauge, but also an OBD II gauge monitoring system. I realized yesterday that the two gauges don't line up and that the OBD II gauge "lags" the "dashboard" on warm-up by 5-10C and then overshoots it ending up around 96-97C. (The "dashboard" stops at 91C or so.) I suspect that the two guauges get their inputs from different places.
Coming home yesterday I hit 80C (on the dash) at 7 minutes at -2C (30F), so it was much faster.
