What is the problem with high temperature at idle?
2 Answers
Rust in the radiator causing poor water flow, which prevents normal heat dissipation. Below is relevant information about high temperature at idle: Reasons for high engine temperature at idle: There is a water pump in the car's cooling system that forces the coolant to circulate. Additionally, there is a thermostat responsible for determining whether the coolant undergoes a small or large circulation. Hazards of high engine temperature at idle: Due to prolonged idling, the engine temperature becomes too low, leading to incomplete fuel combustion, easy formation of carbon deposits, clogging of fuel injectors, and severe carbon buildup can cause piston rings to seize or even break. Prolonged idling also results in poor fuel atomization, where unburned atomized diesel condenses, washing down the cylinder walls and entering the lubricating oil, diluting and degrading it. This causes increased engine wear as moving parts do not receive adequate lubrication.
I often encounter this situation where high temperature at idle is mainly caused by a malfunction in the cooling system. For example, the fan motor might be broken and not spinning, resulting in no airflow for cooling at idle. Alternatively, the radiator could be clogged with dust, obstructing the flow of coolant. Another possibility is a faulty water pump—if the pump isn’t working, it can’t circulate the coolant for cooling. Additionally, a stuck thermostat can also cause the temperature to spike. At idle, the engine runs at low RPM, which naturally weakens heat dissipation. Coupled with running the AC at full blast, the extra load makes overheating more likely. I’d like to remind everyone: first, stop the car and let the engine cool down, then check if the coolant level is sufficient and whether the fan is operating normally. In severe cases, engine components can burn out, leading to costly repairs. Regular maintenance, such as cleaning the radiator and replacing the coolant, can prevent such issues. For safety’s sake, don’t wait until you’re stranded on the road—address the problem as soon as possible.
