Operating temperature too high ?
 

My father in law has a E220 (1995 model). The vehicle used to operate at 80C until the water pump started leaking. Since replacing the pump the temperature peaks at 92C+.Subsequently he replaced the thermostat as well which has made no difference. When driving in traffic the temp fluctuates rapidly. We were told this is normal but I am not convinced, as the previous temperature was much lower than this and stable.We've had the pump rechecked but it seems to be working fine. Please help me establish what the correct specified operating temperature is and why his vehicle ran at a lower temp before replacing the pump?

Thanks from sunny South Africa.....

After replacing the water pump and thermostat - did the system get given a flush and new (MB) coolant???

Any chance of some gunk being displaced and blocking something up???

Cheers

did you forget to reconnect the electric cooling fan? Also, possible air pockets are in the cooling system.

and the stat
 

could be in backwards.

tom w

The car is operating as it is designed to do.

This topic comes up a lot. The thermostat starts to open at 87C and is fully open at 102C. Thus, if the car was consistently running right at 80C, then there was previously a problem with the thermostat opening too early. Normal operation would see the car running AT LEAST 85C-90C on the highway and closer to 100C in traffic.

Now if there are wild temp swings for no good reason other than the normal warming up when stopped and cooling down on the highway, then there would be a problem.

If the original poster was writing from Minnesota or somewhere, I would have to contend that it is running a bit hot...but in South Africa this time of year, that's about right..