For a 2008 Chevy Cobalt, the engine temperature typically operates between 195°F and 220°F. If the temperature gauge rises above 240°F, it indicates the engine is overheating. Continuous operation at high temperatures can lead to serious engine damage, so it's important to address any overheating issues promptly.
thermostat sticking closed then snapping open
could be several things. 1st is the car actually overheating. If so then it could be a stuck thermostat or a bad water pump. If it is not really overheating my bet would be a falty temp sensor. The temp sensor is what actually tells the light to turn on.
That is the temperature at which the cooling fans are coming on, this is common for newer cars. It is not a problem, and should not cause you concern.
Fault temp gauge.
blowed head gasket or cracked head
Where is the temp sensor on a 91 Chevy astro
After the engine has cooled to a certain temp, it should shut off. If it is running constantly, this is an indication the engine is overheating.
Engine overheating. Check the radiator for leaks in the hose pipe or radiator, otherwise the water pump is faulty and will need replacing
Protects, no. The only temp sensor is the coolant temp sensor. The car will run until the engine is ruined if allowed to continue overheating.
Take temperature at radiator when at normal operating temp. to confirm that it is overheating
That light notifies you that one of the gauges is out of its normal parameter. Check the temp (overheating), the voltage (not charging) and the oil pressure gauge (low or no oil pressure).
It's broken