What Causes a Car Radiator to Boil Over? How to Handle It?
2 Answers
There are several reasons and solutions for a car radiator boiling over: 1. Radiator malfunction: When repairing by welding, the damaged cooling core tubes are blocked, reducing the water flow area and decreasing the water output from the upper chamber. 2. Deformation of radiator cooling core tubes: The inner layer of the radiator inlet hose delaminates, reducing the hose's flow cross-section, obstructing water flow, increasing resistance, and decreasing water output from the upper chamber. 3. Excessive scale in the radiator: Core tubes are clogged with sludge, scale, or debris, hindering water circulation. The flow resistance in the upper chamber increases, reducing water volume. Cylinder gasket erosion, cylinder liner cracks, or high-pressure gas entering the water channel can also cause issues. 4. Overly soft water pump inlet hose: The vacuum suction from the water pump causes the hose to collapse; reversed fan blades, broken belts, or faulty water pump impellers prevent forced water circulation. Reduced cooling water circulation area and increased temperature decrease the hose's water capacity, causing the excess cooling water to be expelled from the radiator filler neck, resulting in water spraying.
When I was younger, I drove a truck, and the radiator boiling over was mostly due to insufficient coolant or a blocked system. Engine overheating causes the water to boil and spill out. Quickly turn off the engine and park the vehicle safely, then wait at least half an hour for the temperature to drop. Don’t recklessly open the cap—beware of burns or steam blasts. Check the coolant level; if it’s too low, add distilled water or specialized fluid. Also, see if the fan is running and check the belt tension. Preventive measures: Regularly flush the radiator, keep the coolant fresh, and monitor the temperature gauge in traffic. I remember one time I neglected it and stubbornly kept driving, resulting in a warped cylinder head and a repair bill of over a thousand bucks—a hard lesson learned.
