rovis77

Hi everyone?. Is 93-94 degrees Celsius a normal running water temperature for the C63 AMG W204 in a sunny day and without driving the car fast, I noticed that sometimes it turns the fan on even when I am driving the car slow. Thanks!!!

markov77

Seems about right, Im usually at 92C.

Mort

I run 92C consistently as well. Might be a slight difference in sensors from car to car and only a couple of degrees higher so probably not an issue. What you see on the dash seems to be a smoothed output so I can see the sensor turning on the fan without seeing a reported increase of temperature on the dash.

rovis77

On a sunny day my C63 AMG runs between 93-94 degrees C and at 94 it turns on the fan even with slow driving. So you think this is normal?, I see that your car runs at 92C

Dr.Speedfellow

I run 90.5°C (195°F) water temp during normal driving. I wouldn't worry much about your water temp it seems close to average. If anything just make sure your radiator cooling fins aren't clogged with debris if you have a lot of miles on the car.

Cwagon

Mine like most runs 92-93C

sskhaliq

that's interesting, i run b/w 102-106C (below pic is just reference, not my car )
Do u think there could be an issue?

DRBC43AMG

I think the level you are quoting is a bit high, except if you live in a desert region during a heat wave. I would check the expansion cap that it seals and pressurizes correctly, water level, thermostat opening completely.
For info mine also runs at 92°-93°c in all conditions.

sskhaliq

I'm in Sydney AUS, so temps these days are 15-20C during the day.. not hot at all.
I have been keeping an eye on it, since midway is only 80C
That's a little concerning, it's been twice to MB for servicing and they didn't point out. I'll check cap and coolant level.

Jasonoff

The water temp on the instrument cluster is just a calculated value. It's not the actual CTS value which will be in the 102-110°C range that you can read from OBDII.

If you sift through the BS there's some decent info in this thread --> https://mbworld.org/forums/c63-amg-w...lackboost.html

sskhaliq

So just to update (and embarassed about my ignorance)
My car's oil and water temps are just fine. I was mistakenly thinking of oil temp, whereas this thread was referring to water temp.

Normal temps:
Oil: 106-107C
Water: 92-94C

Mine runs at 106 and 92 mostly. Temp here these days is ~20C and I don't drive hard (only in very brief spurts)

Hope this clears any confusions others (like me!) might be facing.

Chris1953

I know this is an old thread but I was just today watching a video from Tasos Moschatos who was using a decade box feeding different resistance values to the Coolant Temperature input to simulate rising coolant temperatures and comparing the data being read from the OBD2 to that of the instrument cluster. The values differed significantly. I thought this was really strange that the ECU would not accurately provide the actual coolant temperature. The oil temperature is a 1 to 1 match meaning that whatever the OBD2 showed matched the cluster.
For example, when the OBD2 coolant temp showed a value of 114°C the cluster value was 95°C.
When the OBD2 coolant temp showed a value of 117.8°C the cluster value jumped to 105°C.
When the OBD2 coolant temp showed a value of 120.8°C the cluster value jumped to 120°C

One has to ask why would there be such a disparity and then at the very high end all of a sudden it was accurate?

Video link (if you are interested)

Jasonoff

It's essentially a dummy light to corelate to what the masses are used to for water temp.

If you saw 104°C on the dash you'd think the car is overheating when it's actually operating at an efficient temp. So instead it shows 92°C.