This is insteresting. I noticed that some car's temp vary with ambient and some do not. What is suppose to be the norm? Or is there no norm. I thought it would make sense for the temp to be a little higher if you are traveling in warmer temps simply due to heat transfer properties. Thanks to the earlier post on thermodynamics. Perhaps Benzmac has some input on all this.

I read an article in The Star magazine last year where a technician addressed this subject. He said that the newer cars are built to run hotter than older models. Around 100 or so instead of 80.

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Jason Priest
1986 420SEL

420SEL,
If thats the case, then how come my 98 ML runs at 85 no matter what the outside temp is? I still think there is more to it. Maybe everybody's car using different themostat, the age of the coolant? I check with my dealer and they told me the new coolant they put in cars nowadays only requires changing every 100K miles. I don't know if I want to trust them on that one either (sort of like oil change every 12K miles). Hope I am not opening another can of worm here.

95 R129
98 ML320

I wonder if there are "winter" and "summer" temperature thermostats made for MB's. Also, I'm curious about how much sample-to-sample variation there is between thermostats of the same temperature ratings.

I'm not sure if I understand their operation correctly, but don't they simply let water flow through the cooling system to the radiator when the coolant reaches a certain point?

Robert - I asked what might be your next question a while back ("Why not a thermo that opens at a lower temp") and got a pretty detailed explanation about thermal/combustion efficiencies and the thermos being correctly designed as-is. I was looking for a way to get that 20% power back when the motor gets *really* warm and sluggish.

On the topic:
93 190 2.6

Speeds above 45mph, regardless of ambient temp registers 81-82deg (even at 95mph sustained in 115deg w/ 22% humidity - high desert SoCal).

Speeds below 45mph with temps above 70 can drive to 85-100 (high end being stop and go at 95deg ambient + heat from all other cars and pavement). Really noticeable cooling event when those aux fans kick on at 102 or whatever (seems damn high to me, BTW)... At speeds below 45 with weather cooler than 70deg right about 82, may vary depending on how many lights I have to sit at but not much higher than 85.

Never less than 80, unless'n I'm warming her up.

Sustained high speeds always got to the diesel but not to this car. And I have to say that after YEARS of driving other cars I sooo appreciate a guage that actually shows the fluctuations, unlike every american POS I've ever had where you're either "cold", "right in the middle" or "overheated". Same with oil pressure guage, but that's neither here nor there...

Nice thread btw how new is new????
94 C280 runs @ 90c >80 to 114 deg here in Houston.Idle in a SHORT traffic light goes to 100-110c-yikes!
Recently 80f or < runs @ 80-85c. Question, do all the autos have a lower engine cover? which one allude to that may contrubute to higher temps? I rin a fan in the garage towards the grill to get the heat out, guess ever little bit helps.

85 300SD even with that ferin tune up gets only up to 80-83c in 90+f days. Now with 85 or < days runs @ 77-79C. Course when I bought it I used the heavy duty flush that say to run it for 6 hours. Used it all week (as a run about)Should have seen the dark brown mud that poured out! Since then it's been really cool. Thinking of doing it to the C280 just to optimize the cleaning out of the system. My 93 F-150 had same treatment, runs very cool even in the 114f days. LH

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93 F-150 4X4 110k still strong(them oil changes pay off!)
86 Ninja 1000 60k(sold)
85 300SD 168k
94 C280 58K (what a blast to drive, 100+ easy)

Leon, what brand of radiator flush did you use? I know of the Prestone Super Flush or similar, but I'm not sure if it's safe for MB radiators.

I'm assuming that you have to drain the coolant and run it with plain water and the radiator flush? I may have to wait until spring for this; temps here are getting close to freezing at night.

Thanks,

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Robert W. Roe
1984 300SD 173K mi

Hey Rabbit,
Here in columbus ohio where the temperture can differ as much as 35F in 24 hrs, i notice my 83 D-T stays at around 85C pretty much rock soild or up to 95C sometimes in heavy city traffic. But it usually falls back down to 85C or so quickly. I think my gauge is a little sticky around that aera on the gauge anyways!!!!
Brett

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83 300D-T

Hi Robert:
I use the Prestone and there are two types, one a 10 minute flush and the other a Heavy Duty. This one has directins for running it in the engine for 6 hours. I seem to remember that it was ok for aluminum applications. But the best I can tell from all the posts it appears that MBs run hot. Still a bit unsetting, we had a record heat wave in Texas (Houston area). In 114f days the 94 C280 was running at 95-100 and in traffic up to 100C. I do have an idea about the lower engine shield. Will play with the idea to see if the added air flow helps. Will keep you posted in a few weeks. Night shift! Regards LH

quote:

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Originally posted by Robert W. Roe:
Leon, what brand of radiator flush did you use? I know of the Prestone Super Flush or similar, but I'm not sure if it's safe for MB radiators.

I'm assuming that you have to drain the coolant and run it with plain water and the radiator flush?

"YES that's what I did."

I may have to wait until spring for this; temps here are getting close to freezing at night.

Thanks,

---

It seems very odd to me that MB cars are supposed to have high temp .Why does my 2002 Lincoln Towncar never budge from 80
degrees in 100 degree weather, a/c blasting stuck in Holland Tunnel ? Shouldn't a MB be better ? I have a 300 E and a 560 SEL and I think they're the best cars I've ever owned but there has to be a repair issue to fix high temp on MB's. Also, how do MB's in middle eastern countries cope with "110 degree in shade" weather ???

A lot of american and asian cars use temperature switches as opposed to the Mercedes temperature gauge.

On these cars that use the switch as long as the cars are not deemed to be overheating or near overheating the needle stays at center. When overheating occurs the needle goes to the overheating portion of the scale. Something reassuring about gauges that stay in their neutral or center reading.

300SDL - about 90C + or - 2C open road; 100C + or - 5C in city traffic. ML320 - about 85-90 all the time.

__________________
Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

1999 SLK230/auto 49k miles

Amb temp 90'f
Coolant temp: 85'c at highway speed
95'c sitting in traffic

NP

__________________
"If it's not BLOWN, it sucks"

1998 C280 Sport - Member 744 Crew
1988 Toyota MR2-Kompressor(No. 3) 168K+ Miles
Prior MB Cars 1974 450SLC & 1985 190E 2.3

Click This Link - IOS, Greece - Get Your Phreak On

Hi, the temp on my car is:

1996 E230 W210.

City Driving with Traffic ranges from 97-110 C BTW, I live in a hot humid asian climate.

Never went more than 110 but is normally around 98 C.


I am quite horrified by this since it is quite close to the red mark.

If this is normal for a Benz, I hope they change this design coz its making me a bit paranoid.

Strangely, my car does the opposite, that is it runs too cool, regardless of the ambient temperature(which varied between 16-34 degrees C (that's 60-93 degrees F) this spring and summer).

The small plate in the engine bay gives the normal temp as between 60 and 80 degrees Celsius.

At highway speeds, the gauge stays at 60C or a bit higher, when slowing down it raises slowly towards 80C. After 5 hours of highway driving, when entered city, it raised to 80C and even one hair above.

Never checked the water temp with a thermometer to see if the sensor reads well, just trusted the "60-80C" recommendation.

The car doesn't have (and never had) auxiliary fan, just the main belt-driven fan. Coolant was standard antifreeze(unknown brand) + water, heavily diluted by adding more distilled water. Oil is 10W40, mineral (completed once with 1 liter of 10W40 semi-synthetic).

My uncle's 300E (from 1988, with A/C and single auxiliary fan) actually runs slightly warmer, around 85C. Paradox?

~Regards,

Nautilus

__________________
1990 260E Sportline (that's 300E 2.6 for our American friends) -> sold
2001 E320 4Matic Elegance -> my Dad's daily drive
2005 Seat Leon FR 1.8T