What are the causes of high engine coolant temperature?
2 Answers
The causes of high engine coolant temperature are: 1. Leakage or insufficient coolant in the cooling system; 2. Inaccurate or malfunctioning temperature gauge; 3. Excessive scale buildup in the cooling system, resulting in poor heat dissipation; 4. Blockage of the radiator guard mesh or radiator core ventilation passages by debris, leading to inadequate cooling; 5. Loose or broken water pump or fan belt; 6. Damaged water pump, incorrectly installed or deformed fan blades, or damaged fan shroud; 7. Thermostat stuck in the closed position; 8. Prolonged engine overload operation or excessively delayed fuel injection timing. An engine is a machine that converts other forms of energy into mechanical energy, including internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, and electric motors.
Last time I was on a long-distance drive when the temperature gauge suddenly shot up to red, so I panicked and pulled over to the emergency lane. Upon opening the hood, I found the coolant was almost depleted, and the antifreeze reservoir was half empty. This situation is most likely due to a coolant system leak—possibly from aging, cracked hoses or a rusted-through radiator. If the coolant level is sufficient but the fan isn’t spinning, it’s almost certainly a blown fuse for the electric fan or a faulty temperature control switch. I’ve also encountered a stuck thermostat that wouldn’t open, preventing hot coolant from circulating through the radiator. The worst-case scenario is a blown head gasket, where oil and coolant mix into a milkshake-like substance—that’s an expensive fix. It’s important to develop the habit of checking the coolant level before starting the car in the morning and monitoring the temperature gauge while driving.
