What Causes Coolant to Boil?

[Nicholas]

The reasons for coolant boiling include blockages in the coolant circulation system, insufficient coolant, or radiator malfunctions. Here are the detailed explanations: 1. Blockages in the coolant circulation system: Any blockage or leakage in the entire coolant circulation system can lead to engine overheating and coolant boiling. Immediate repair is necessary upon discovery of such issues; otherwise, it may result in engine bearing failure or piston seizure, significantly increasing repair costs. Solution: Visit a 4S shop for inspection and repair. 2. Insufficient coolant: Coolant naturally decreases over time with use. However, if the coolant level drops too low, cooling efficiency will decline, leading to coolant boiling and even engine overheating. Solution: Promptly replenish the coolant. 3. Radiator malfunction: If the radiator has been damaged and repaired, insufficient cooling surface area can almost certainly cause coolant boiling. Additionally, poor internal flow or obstructed external ventilation in the radiator can also be problematic. These issues, if severe, can affect the engine, causing its temperature to rise as well. Solution: Visit a 4S shop for inspection and repair.

[Aniyah]

I've been driving for over a decade. Once during a summer road trip, I noticed the temperature gauge suddenly spike into the red zone. I immediately pulled over to check, and when I opened the hood, steam was billowing out with the coolant boiling. After consulting a mechanic friend, I learned the possible causes could be insufficient coolant or a leak, or the electric fan not working leading to poor heat dissipation. If the fan belt breaks, the cooling system simply can't function. Additionally, a clogged radiator or stuck thermostat can restrict water flow circulation, causing temperature to spiral out of control. The worst-case scenario is that if you don't shut off the engine immediately and wait for it to cool, the engine block could crack, resulting in astronomical repair costs. That time, I managed by just adding coolant, but I'd advise against copying my temporary fix—it's better to call a tow truck and have the entire cooling system professionally inspected.

[LaChase]

If you encounter coolant boiling, don't panic. I usually turn off the engine immediately and pull over, then turn on the hazard lights to warn other vehicles. Next, open the hood to dissipate heat, but avoid touching hot components. Check the coolant reservoir's fluid level—if it's empty, there might be a leak, such as from aged or cracked radiator hoses. Also, see if the cooling fan is spinning, as fan failure is quite common. Insufficient pressure in the radiator cap can also lower the boiling point. For daily prevention, I make it a habit to check the coolant's color and level monthly. If it appears cloudy or foamy, replace it as soon as possible. Regularly cleaning dust to prevent blockages can reduce 80% of sudden issues.

[DelJohn]

Coolant boiling indicates severe engine overheating. Failure to address it promptly can lead to burned engine components and chain failures. I recommend immediately turning off the engine and letting it cool to avoid thermal stress damage. Common causes include poor heat dissipation, such as fan failure, water pump damage, or blocked coolant circulation; it could also be as simple as low fluid levels, requiring regular checks. Safety first - prioritize life preservation and have the vehicle towed to a repair shop for comprehensive inspection.