What's too high for the water temperature? I notice the gauge goes all the way up to 120 degrees celsius before it goes red. I'm down in hot as heck arizona and it goes to about 110. Should I be worried? This is after running for three hours at 110 degree F weather running the a/c on full blast. Thanks Mercedes Experts!

 

My C280 stays between 80 C and 100 C, If you go no higher then 110 C I would think your safe. But if your going into the red, I would get my car to the dealer fast their is a problem. If all things are normal, many post of this board say 80C to 110C is OK, but 120C and into the red is a problem. At least the heat is Arizona is dry. Driving in 110 degree weather for three hours, I assume highway all the time and the AC blowing away is OK? But if you are going into the red for any reason as I said run don't walk to your dealer. or a GOOD Mercedes tech shop.

 

MBs are more like motocycles...temperature rises immediately if you come to a stop light.

Typically the needle stays in the middle which is 80C. Summer time city driving, it reaches 90C from time to time. It's OK.

I would check a few things if goes over 90C. These things are simple ones...

- level of coolant
- activation of fan

Low level of engine oil is also another factor, but it has to be really really low to increase the temp.

Your coolant in the system could be 100% anti-freeze. If your area never freezes, drain it, and put plenty-o-water with very little anti-freeze coolant.

 

This is normal for an MB - unlike japanese cars that have temp gauges that don't seem to move. Just check coolant level and auxilliary fans. Manual also states this.

 

110-120 IS TOO HIGH!! Isn't that an overheat?

Even though you are in arizona, that is still too hot!!

Things that might be at fault in your car (check in order of importance)

1) Visco fan -- if the main (biggest fan) spins without tension, then it is broken. There should at least be a little tension to stop the fan if you spin it rather than spinning too loose.
If possible, try to get a tropicalized Visco fan from SACHS or an aftermarket supplier.
2) Thermostat -- if the temp rises immediately, then it is broken.
3) check auxiliary A/C fans. It might not be spinning fast enough or not engaging at all.
4) Dirty radiator -- Have it removed and cleaned professionally.
5) coolant change -- Still, a 50-50 coolant mix is preferred so that the water will not boil.
6) Coolant loss -- Check if you have leaks. Most are visible if the car is already hot with water pressure.

I live in Asia (philiippines) and it is very hot and humid here. My car runs at 80-85 at most

 

BTW,
If ever the visco fan (clutch fan) is broken, try if you can find the brand TRUCKTEC. It is another supplier of those clutch fans. It is a lot cheaper and they have a tropicalized version. I got mine for about $92.

 

I agree, my car never gets that hot here in Phoenix. Usually the hottest I get is 100*C. Everyone has good points on what to check, here in Arizona you can do a good concentration of water in your coolent as long as your not in Northern Arizona.

Nick

 

I'm in crummy Sierra Vista, thanks for all the advice!