could be the temperature sending unit
Thermostat is sticking.
It is for the Temperature gauge, it feels more balanced than being either side of the middle
replace the printed circuit board behind the tach gauge. $15.00
A temperature gauge, that always read the maximum temperature, is usually not connected to the temperature sensor. The wire between the gauge and the sensor must be broken.
get a new temperature sensor.
When operating properly, the cooling fan stays on until the temperature drops to normal.
Your check gauge light comes on if : your coolant temperature guage shows the temperature is high your oil pressure gauge shows the oil pressure is low or your fuel gauge shows the fuel tank is near empty
Most likely cause is a failed engine thermostat.
A common cause is the thermostat being stuck in an open position.
Your car engine isn't getting up to the desired temperature, about 130 degrees Fahrenheit.
ect sensor bad
on the cooling reservoir ther is a plug that registers the level. check this.