Coolant Temperature range?

File: 2011 Fiesta (12).jpg (28KB, 320x240px) Image search: [Google]

28KB, 320x240px

Been watching coolant temperatures on the Fiesta since its summer and it doesn't have a temp. gauge. In the mornings it's normally 188-194 F. Then in the afternoon it got up to 208..... and climbed to 215 degrees briefly before going to 198. I assume the thermostat opened? It tracks quickly, but not instantaneously.

Is this the thermostat being closed a little too long? 212 is when water boils at atmospheric pressure. Coolant, under pressure boils higher than that, but still, 200+ is flippin hot for an engine right? My mercury Mountaineer stays near dead constant 186-194, from slow cruising to wide open throttle and hard driving.

A/C on or off doesn't significantly alter temps. Heater ON seemed to increase temp, before lowering it marginally.

So much for a gas sipper that can't be trusted for a weekend trip... The Fiesta has had the radiator fan motor fail, causing overheat & blew head gasket....