Engine Temperature
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Joined: Jun 2002
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Engine Temperature
I'm looking at the display, and temperature is shown as a horizontal bar graph. After the car warms up, the temperature is around 90 degrees C. Is this temperature....... the engine, the coolant or the oil ?
On a cold day, if you have the heat on high, and the temperature doesn't go above 80 degrees C , does this have any negative effect on the car's performance or the car's gas mileage ?
On a cold day, if you have the heat on high, and the temperature doesn't go above 80 degrees C , does this have any negative effect on the car's performance or the car's gas mileage ?
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Joined: Nov 2001
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From: Gaithersburg, MD
2002 C240 6-spd (ret)
Funny you started this thread, I was going to ask a different question on the same idea.
The bar graph shows the coolant temp. In warmer weather, mine usually sits around 90 degree also (Celsius). In cooler weather, I think 80 is fine.
My question to others is this. This is my 2nd winter, and I don't remember the coolant temp warmup behavior from last year. If I'm idling in traffic for a while after startup, the temp rises some, but doesn't even reach 80. This morning, it was around 60 for about 15 minutes. Then as I started driving at speed, the temp rose to 80. I seem to remember the temperature rising more quickly to 80 last winter. I'm in the DC area, and the temperature's been around 25-35 in the mornings. Has anyone else noticed how quickly their engine warms up? I've got a C240.
PS. Hope I didn't "steal" your thread :o
The bar graph shows the coolant temp. In warmer weather, mine usually sits around 90 degree also (Celsius). In cooler weather, I think 80 is fine.
My question to others is this. This is my 2nd winter, and I don't remember the coolant temp warmup behavior from last year. If I'm idling in traffic for a while after startup, the temp rises some, but doesn't even reach 80. This morning, it was around 60 for about 15 minutes. Then as I started driving at speed, the temp rose to 80. I seem to remember the temperature rising more quickly to 80 last winter. I'm in the DC area, and the temperature's been around 25-35 in the mornings. Has anyone else noticed how quickly their engine warms up? I've got a C240.
PS. Hope I didn't "steal" your thread :o
Last edited by MarkL; Dec 4, 2002 at 09:16 AM.
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Joined: Sep 2002
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From: Ohio
2010 C300 4matic
Re: Engine Temperature
Originally posted by Jerry MB230K
I'm looking at the display, and temperature is shown as a horizontal bar graph. After the car warms up, the temperature is around 90 degrees C. Is this temperature....... the engine, the coolant or the oil ?
On a cold day, if you have the heat on high, and the temperature doesn't go above 80 degrees C , does this have any negative effect on the car's performance or the car's gas mileage ?
I'm looking at the display, and temperature is shown as a horizontal bar graph. After the car warms up, the temperature is around 90 degrees C. Is this temperature....... the engine, the coolant or the oil ?
On a cold day, if you have the heat on high, and the temperature doesn't go above 80 degrees C , does this have any negative effect on the car's performance or the car's gas mileage ?
Super Member
Joined: Jul 2002
Posts: 678
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From: Vancouver WA
'14 GLK250 Diesel
The V6...
...is a slow warmer-upper, if you are looking for it to go much over 60-70 C quickly. I've occasionally put up the temp display when starting from cold just for yucks, and yes, it seems to take a long time [our avg temps for this activity around here have been about 55 F] to hit and stabilize at the temp that is average for longer trips.
I really believe this is nothing to be concerned about, and until this thread started, haven't considered it to be worth mentioning. The coolant temp is much less critical from MB's perspective than the catalyst getting up to temp quickly - this is what holds startup emissions down, and startup is when most emissions occur.
And even at these relatively low coolant temps, the heater box starts putting out ergs very quickly. I see nothing here that even remotely constitutes a problem.
I really believe this is nothing to be concerned about, and until this thread started, haven't considered it to be worth mentioning. The coolant temp is much less critical from MB's perspective than the catalyst getting up to temp quickly - this is what holds startup emissions down, and startup is when most emissions occur.
And even at these relatively low coolant temps, the heater box starts putting out ergs very quickly. I see nothing here that even remotely constitutes a problem.
Senior Member
Joined: Aug 2002
Posts: 490
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From: Canada
05 CLK 500 cab
The 1.8 engine is also slow to warm up -- maybe 10-15 minutes of suburban driving at an outside temperature around 50. I agree that it does not seem to impair heater efficiency.
Cold engines can use more fuel because the mixture is enriched at start-up to promote combustion. Also the oil is colder, which increases resistance in a cold engine as the outside temperature drops. Neither issue should be significant at coolant temperatures around 80 C. My "After Start" screen indicates lower-than-normal fuel economy in the first few minutes, but maybe there's another reason.
Cold engines can use more fuel because the mixture is enriched at start-up to promote combustion. Also the oil is colder, which increases resistance in a cold engine as the outside temperature drops. Neither issue should be significant at coolant temperatures around 80 C. My "After Start" screen indicates lower-than-normal fuel economy in the first few minutes, but maybe there's another reason.
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Joined: Dec 2001
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From: Canada
Originally posted by lars
My "After Start" screen indicates lower-than-normal fuel economy in the first few minutes, but maybe there's another reason.
My "After Start" screen indicates lower-than-normal fuel economy in the first few minutes, but maybe there's another reason.
