There are a few possible reasons; A bad thermostat will not allow the water into the engine. This is the most likely. The radiator could be clogged and not allow the water to circulate and cool off The engine itself could have water line clogged A bad water pump
Check the engine coolant... Is it full? yes coolant level is full
The coolant level is set by the level in the coolant reservoir. There is a line for the level if the engine is cold and a line for if the engine is up to temperature. You should fill it to the corresponding line.
If there is a cap on the radiator you can check to see if the radiator is full , and if it isn't , " top up " the engine coolant . Otherwise , you check the engine coolant level at the engine coolant reservoir when the engine is cold and maintain the level at the cold mark
The coolant level is checked at the coolant tank in the passenger front corner of the engine compartment . The coolant level should be up to the cold mark when the engine is cold . The radiator should be full so its covering the top plate .
The best place to start would be to check the coolant level in the radiator. If the coolant level is low, fill to full level. If the engine is not reaching the normal operating temp, then the thermostat is bad. Just replace the thermostat with a new one.
If the engine code indicates that the coolant level is below the coolant sensor despite the reservoir being full, it could be due to a faulty coolant level sensor itself, which may need replacement. Additionally, there could be a wiring issue or a loose connection affecting the sensor's ability to accurately detect the coolant level. It's also possible that air pockets in the cooling system are preventing proper sensor readings. Lastly, the engine control module (ECM) could be experiencing a glitch that requires a reset or reprogramming.
Possibly low coolant level or blown heater core.....also check thermostat CHECK COOLANT LEVEL FIRST. IF FULL THEN MOST LIKLY YOU NEED A THERMOSTAT.
To check the coolant level on a 2003 Suzuki VL800, locate the coolant reservoir, which is typically found near the right side of the bike. Ensure the engine is cool, then visually inspect the coolant level through the reservoir's transparent markings. The level should be between the "Low" and "Full" marks. If necessary, add the appropriate coolant mixture to reach the proper level.
To check the coolant level on a Honda Rancher 350, first ensure the engine is cool. Locate the coolant reservoir, typically found near the radiator, and inspect the level against the markings on the side of the reservoir. The coolant should be between the "low" and "full" marks. If necessary, add the appropriate type of coolant to reach the correct level.
Check your coolant level again to see if the level has gone down. If it has check your engine oil level to see if it is above the normal full line. If it is this might mean you have a bad head gasket. I had a 92 grand prix that was not over heating but i was losing coolant, bad head gasket.
Add coolant to the full cold line on the coolant reservoir when engine is cold.
low engine coolant level, your heater core is at the very top, so if its not full to the very top it wont work. add coolant and bleed system.