Normal Operating Temp of 300D - PeachParts Mercedes-Benz Forum

mslipac · #1 11-28-2003, 10:10 PM

sorry for so many qustions guys!!!

my benz reads to the notch between 175 and 205 on the gauge for most of the time or little bellow

is that hot or okay

Thanks

#2 11-29-2003, 12:42 AM

Is that 175* and 205* in *c or *f? This can make a big difference.

If it's F, it is the normal range.
If it's C, then it's VERY hot.

Mine sits at 83*c, just slightly above the 80*c mark.

P.E.Haiges · #3 11-29-2003, 12:55 AM

Mslipac,

Sounds about right. Engines are supposed to run hot. I read that the Navy did a test and found the optimum running temperature was about 300*F for Diesel engines. Of course this was for large Marine Diesels.

I think the temperature cars run at is related to the boiling point of water. As long as they don't boil over, they are not too hot. Notice where the red area is on your temp gage.

P E H

Ken300D · #4 11-29-2003, 09:26 AM

Also, in comparing your temperature readings to other folks, please keep in mind that the old MB temperature gauges are not exactly scientific instruments.

It could be substantially off.

For example, the gauges on both my 617-engined cars jump up and down and change their reading. I presume this is due to an electrical connection or resistance somewhere.

So don't get too upset and replace the whole cooling system based on the MB gauge. Chances are the stupid gauge will read the exact same thing with all new components.

Ken300D

Gurkha · #5 11-29-2003, 09:39 AM

83C is pretty much the average I get with my OM616 turbo, although on hot days around 45C the needle creeps up to 90 and this is where my aux fan comes on. Funny that all the other Japanese vehicles I own, the temp never seems to creep up over 80C.

gsxr · #6 11-29-2003, 02:36 PM

My 1984 300D Turbo, with recent radiator, thermostat, coolant flush, fan clutch, temp sender, etc etc stays at 85-90C almost ALL the time. Sometimes on really hot summer days with the AC on max it might get to 95C, and on cold winter days with heater on max it might be 80C, but that's not often. The gauge should never jump around - that is an indication of electrical problems. Mine is rock steady. I've never seen this car get to 100C, ever (that's 212F btw). Any W123 diesel with the cooling system operating at full capacity should be the same way, IMO.

FWIW - the later OM603 turbos were not quite the same. They made more power (and therefore more heat), and they can get to 100-105C under more extreme circumstances, where the OM61x would not. Keep that in mind when comparing engine temps, make sure the numbers you're discussing apply to the correct engine!

lietuviai · #7 11-29-2003, 04:04 PM

My '85 300D runs at about 80°C most of the time and can get up in the high 90°'s on hot days (90°F and up) with the A/C running and going up a steep grade. This is in a car that still has its original radiator, thermostat and fan clutch. The water pump and coolant are the only newer components in my cooling system.

mslipac · #8 11-29-2003, 08:28 PM

yeah the reading is in 'F

this car is awsome I am one happy guy right now cruzing down the highway in the car that I was looking to get my hands on for about 3 years now

the cars that I looked at before were either too expensive or rustbuckets!!!

#9 12-01-2003, 04:39 AM

My cars thermostat is stuck open! Once it finally warms, its usually around 80; 83, 95, 78, etc. I am, on the other hand, freezing... It all get fixed in 01/04.

redbaronph123 · #10 12-01-2003, 04:59 AM

Quote:

Originally posted by Gurkha
83C is pretty much the average I get with my OM616 turbo, although on hot days around 45C the needle creeps up to 90 and this is where my aux fan comes on. Funny that all the other Japanese vehicles I own, the temp never seems to creep up over 80C.

that is because most jap cars dont use the dynamic temperature gauges. It basically stays in teh middle all the way... and it only goes up if you really have trouble with your cooling. Hence 80*c or 90*c or even 100*c.. no diff for jap cars..

as for our old cars.. we have the dynamic temperature gauges that basically tells us "exactly" (duh!.. not really!) the temperature our engines are operating at. I kinda like this rather than the phantom gauges where it is in the middle all the time. Though i think newer MBs are using this already.

P.S. forgot to post in-topic... my temp basically stays a little above 80*C.. goes around 90*C on very hot days.

Gurkha · #11 12-01-2003, 07:07 AM

This is the first time I am hearing this, as far as I can tell if I were to block the radiator which I have tried as a test of my Nisaan, the temperature goes up accordingly and even on test benches, both MB and Nissan temp gauges exhibit the same specs, in a tub of hot liquid, the temp reading is same for both the MB as well as the Nissan. Why would the Japanese joepardize their engine with a thing like this.

The fact of the matter is that unlike MB and other Euro cars which are specificaly designed to run in cooler Euro weather, Japanaese cars have much superior cooling systems and in general tend to run much cooler. I have taken both the vehicles as well as my friend's G-Wagen with OM 617 turbo engine to the desert in Rajasthan and can tell you that between the three, only the Nissan help up its poise at 56c ambient outside temp. Gotta give the Devil its earned due in this case.

rickjordan · #12 12-01-2003, 09:29 AM

Mislpac, isnce all our cars temp. gauges are in C, and most don't know how to convert to F, where in C does your gauge sit at.

mslipac · #13 12-01-2003, 10:05 AM

175 degree Fahrenheit = 79.4444444 degree Celsius

and I would say mine sits about 190 - 195'F so that's

195 degree Fahrenheit = 90.5555556 degree Celsius

Toblin · #14 12-01-2003, 10:36 AM

"isnce all our cars temp. gauges are in C, and most don't know how to convert to F, where in C does your gauge sit at".

Not so. The temp gage in my '79 300D is in Fahrenheit.

jfikentscher · #15 12-01-2003, 10:36 AM

In the summer mine ('87) runs just over the 80 mark, but in the winter it usually does not get over the 60 mark. I must need a new thermostat. Probably it is stuck in the opem position.

My son's car ('82) stays around the 85-90 mark all the time.

Joe