I had similar problem with a Mercury Tracer I owned I had two problems with mine, One the thermostat was faulty(was old and rusted out) and the temperature sending unit wasn't working right ( Fan did not come on at needed temperature 205 degrees) so I had to replace them both.
Hope this helps
Water pump defective.
If your radiator isnt leaking and car is having a over heating problem and coolant spewing out. Chances are your thermostat needs replaced. possible the radiator needs to be flushed. But more likley its thermostat
cooling system needs flushed out and a new thermostat installed, also if the radiator is still original it probably needs replaced or rodded out.
Could be your electric fan on the radiator is shot, or the relay is bad.
you must be a wierdo.stupid.
Have flushed complete cooling system replaced water pump radiator thermostat clutch fan added 2gal straight anti freeze then filled to capacity with water and truck is still over heating. What else could possibly be wrong
you might want to check for a blown head gasket or a cracked head or block. espically if it loosing water out of the radiator with out leaking on the ground.
Test gauge function with a mechanical gauge to get actual engine temp.
Low coolant? System air bound? Hoses collapsing under pressure? Water pump not circulating coolant?
System airbound? Coolant level? Temperature control cable?
It could be a clogged radiator or cracked head or bad head gasket.
could be the water pump That is a typical symptom of an air lock in the cooling system