It depends on where the sensor is, what thermostat you have and what coolant mix you are running. If its constant and not looseing coolant, you might try a cooler thermostat and see what happens. Try some of the Water-wetter addatives, they do help cool engines. 210 is about normal for a new computer controlled engine, its a tad warm for this type of engine. Have you checked the water temp in the radiator with a good thermometer? your new gauge could be a few degrees off. Joe