1985 - 500 SEL When starting the engine from cold, the coolant temperature slowly rises until it is up in the red zone, above the 120C marked on the gage. The temperature stays there for several minutes, then drops down to 80C where it will stay. The coolant level is correct and the thermostat has recently been replaced. Is the new thermostat sticking or is this normal behavior? It worries me to see the temperature gage that high.