98 E300DT Engine Temperature

Hey all,

Picked up a 1998 E300DT a couple months ago. The engine never seems to go over 80 degrees C. On real cold days, it stays right under the 80 mark.

My 96 E300D used to always run at 95-100 degress C - no matter what time of day it was or what the weather was.

Is this normal for my '98? Or is it too cold?

If the temperature rised to between 80 - 100 will my mpg improve?

Thanks in advance!

[sokoloff]

Mine usually sits right at 80 or a hair below. I don't think it's ever gotten to 90.

Len
'99 E300TD 85,000 miles

[superlite17]

Your E300 is Perfectly Healthy. Mine runs the same, right at 80 C and never really gets any hotter here in San Diego.

Paul
___________
98 E300

[Eggburt]

Maybe it has something to do with the addition of an oil cooler in 1998. Mine stays at 80 or bit below, as well.

[nhdoc]

Yes, that is normal. In fact, in really cold weather, like I have here in NH, it takes about 20 minutes of driving before the engine gets up to even near 80. There is so much taxing the cooling system (fuel heater, cabin heater and winshield washer heater) that by the time all of these sytems get warmed up the car barely needs the radiator in winter.

My car had been running warmer at idle in summer until I discovered the auxilliary fan was kaput, and after I replaced it the car ran perfectly well at 80 again and the AC at idle was improved too.

[Matt L]

I had a failed auxiliary fan on my '96 E300 also, which not only caused the engine temperature to rise to 95 at times, but also seems to have caused a loss of refridgerant.

With the fan, the temperature runs about 90 with the air-conditioner on, and about 85 or below without it. And yes, the air-conditioner is much happier.

These temperature are as reported by N22, which indicates slightly higher than my dashboard gauge.

[Jim H]

Originally Posted by bisric

If the temperature rised to between 80 - 100 will my mpg improve?

Perhaps, but it would be a minimal change, not worth the effort to raise the temperature by playing with thermostats...

[aklim]

Mine used to run a C*** hair or two below the 80 mark all day long. However, once I had my ECM reprogrammed and run it in hot weather, it goes past the 80 mark by 2 C*** hairs above in spirited running.

[98E300man]

Ditto. Mine never strays above 80. If it did.....

98 E300 85k

[turbodiesel]

In the blistering heat of this summer where it would get to 105F ambient temp.. the diesel would get to 90-95C. Normally it is a hair below 80C.

[raMBow]

Mine runs about a needles width below 80 all the time. Only time I ever saw it over, by about 2 needles width, was sitting in crawling traffic for about 45 minutes in Branson, MO. It was over 100 degrees outside with AC blasting. Probably sucking up half exhaust from the car in front of me.

[aklim]

Bottom line, Richard, you are fine. Please paypal us all $70 each for our highly technical answer that took lots of research. Usually it is $95 but since you are a board member, it is $70 for you.

[DieselAddict]

If you're running below 80C all the time, it's probably a good idea to check the thermostat. My car with a new thermostat and water pump runs at 80-90C even in the winter, but it does take quite a long time to reach it, much longer than my 240D which is up and running at 80C in only a few minutes of driving.