What's the reason for high coolant temperature?
2 Answers
The full name of antifreeze is antifreeze coolant, meaning it has the function of preventing freezing. Antifreeze can prevent the coolant from freezing and cracking the radiator or damaging the engine cylinder block or head when parking in cold winters. There are three main reasons for high coolant temperature: 1. Improper addition and replacement of antifreeze: This can cause early blockage of the engine water passages and radiator, leading to high water temperature. Antifreeze should be replaced every two years, and only original antifreeze should be used during replacement and addition. If the concentration is too high, it can result in poor heat dissipation and engine overheating. 2. Leakage in the cooling system components: If there are leaks in the cylinder block, cylinder head, cylinder gasket, heater radiator, water pipes, rubber hoses, or drain switch, it will reduce the water volume and decrease the ability to absorb heat energy from the cylinder, causing the coolant temperature to rise excessively. 3. Air in the pipes, idling operation.
I often encounter the issue of high coolant temperature, most commonly due to insufficient coolant or leaks. Once, I found a loose hose connection at the radiator causing a leak, and topping it up fixed the problem. Additionally, a clogged radiator or a non-functioning fan can cause the temperature to spike, so it's necessary to check if the cooling fins are blocked by debris. For older cars, the water pump might fail or the thermostat could get stuck—the water pump is like the engine's heart, failing to circulate coolant, while a stuck thermostat blocks the cooling passage. The most troublesome scenario is a blown head gasket, where exhaust gases enter the cooling system, causing the temperature to skyrocket immediately. This often happens in summer traffic jams—when the coolant warning light comes on, you must pull over, or else engine seizure could lead to costly damage. When stopping to cool the engine by opening the hood, remember never to open the radiator cap directly, as the escaping steam can cause severe burns.
