Installed new thermostat, but problems.... - Page 2 - PeachParts Mercedes-Benz Forum

Ali Al-Chalabi · #16 03-13-2004, 10:12 AM

Yes, if it is half way between the 80C and the next line, you are golden. That next line corresponds to 100C. Halfway between would be 90C

If it intersects with the 8 digit hafway, that looks to be a little more than 1/4 of the way up the scale from 80C to 100C and should probably to correspond to 85C to 87C.

Looks like you are in good shape.

Benz300 · #17 03-13-2004, 10:39 AM

sounds good. thanks for everyone's replies here. Hopefully this will help others whose thermostat isn't working properly but they don't realize it untill after they experience heating issues during winter weather. Changing the thermostat was really simple procedure.
However, as a preventive measure, whats the duration or mileage interval that the therm. should be replaced even if it';s funcitioning properly just to avoid it's break down . ?

Ali Al-Chalabi · #18 03-13-2004, 10:48 AM

As a form of habit, I just change my thermostat when I do a coolant change every 2-3 years. When there is no coolant in it, all there is to do is unbolt the housing, stick the new one in, put in a new seal and put the housing back on.

Benz300 · #19 03-13-2004, 11:59 AM

Ali,
I notice you have the c280. were you referring to the maintenance of your C or do you have a w124 as well that you havent listed ?

haasman · #20 03-13-2004, 01:08 PM

As a side note- I went through a similiar confusion with the 300e. It seemed to run cold, never indicating anything above 80C even on hot days. Just out of curiosity, I removed the temp sending unit wire and reattached it. The temp suddenly went to half-way between 80-100. I replaced the sending unit.

I guess the moral is to be sure what is indicated is what is really happening.

haasman

Ferdman · #21 03-13-2004, 01:40 PM

For what it's worth the needle on the temperature gauge of our 1991 300CE and 1992 300CE reaches the top of the "8" (or is horizontal) during the winter months and drops down to the center of the "8" at times.

Ali Al-Chalabi · #22 03-13-2004, 03:20 PM

I was referring to the maintenance of my C280.

Although I do believe that they both use the same thermostat. I think a lot of Mercedes seem to share a common thermostat.

Benz300 · #23 03-21-2004, 12:01 PM

Fredman,
I've experienced the same issue even with the two new thermostats that I've replaced. but I guess going by what other's have posted, it's OK as long as the needles is above the 80 mark. However I remember the original thermostat always used to give a constant reading, around 90deg. driving or standing idle.
these new ones drop the temp. atleast 5deg when the car is running and the temp clibs when the car is idle.
i'm wondering if it's just the thermostat or do other parts need to be looked at for this ....

Duke2.6 · #24 03-21-2004, 01:23 PM

These thermostats appear to "drift" as they age. When new, my car ran pretty consistently at 90C on the freeway at any temperature. Now it runs at 80C until the ambient temperature is over 70-75. At that point it increases and runs up to 90C as the air temperature increases to 90F or more.

Of course, in traffic it will heat up to about 100C and I know the fan clutch engages from the noticeable fan roar at about 2000 as you accelerate.

The thermostat "drift" to the down side is no big deal.

Duke