My 2005 bonevile gxp temp gage is not working correctly it is at 280 degrees and the coolent temp is not

Bad sending unit in fuel tank, or temp. gauge stepper motor bad

Need to get a new coolant temp sensor

check your coolent .if your coolent is low you wont get any heat try this frist

195-235 degrees F

Bad gage

The needle on the dash gage can be pulled off and slipped back onto the stem of the gage. First get an accurate temp gage to be sure what the engine temp is operating at. Then remove the face of the dash gages and remove the needle and place it back onto the stem to reflect the current correct engine temp and you should be good.

me I would check the thermostat it may be sticking if it wereto stick shut it would cause the gauge to act iratic and even if you have just replaced it it still may be bad my advice it will cost a few dollars more buy it from the dealer they always seem to work and last longer if not that may be plugged up radator hope for the thermostat

is coolent boiling over into resevor? or is it just the temp. gage shows its running hot?

should be fine as long as the gage goes up and down and you get heat it should be fine make sure you consider the outside temp. as the engine starts it will heat up get really hot the the thermostate opens and the gage will fall and should but not always stay low it could just be the ip gage.

under the relay cover should tell where they are. you could switch one with another next to it to diagnose. then maybe ck cooling fan itself by unplugging and powering it up manually with power and ground to connector. could even be coolant temp switch ocated on engine. is the engine lite on?