The gauge isn't the problem. 219 deg. doesn't seem awfully high considering that your stock thermostat is 190 deg.. The cooling fan doesn't come one until about 240 deg (if I remember correctly). There is also a possibility of an air bubble in the system, but that should eventually work its way out. I would replace the gauge sending unit. It is not the same as the coolant temp sensor. The gauge sender is only for the gauge. It is about $15.00 and is the small one with the single post that is right about under the throttle body on the hose spout. While you're at it I would replace the thermostat with a 180 deg. one. That is also easy to replace and is right there by the temp gauge sender. I run the 180 on the Duratecs with no noticable loss of heat here in the northeast winters.
