What Causes a Car Radiator to Boil Over and How to Handle It?
3 Answers
Here are the reasons why a car radiator may boil over: 1. Insufficient water level. Prolonged water circulation can gradually lead to water loss, causing the radiator to run low on water. If not checked and refilled in time, this can easily result in the radiator "boiling over." 2. Radiator corrosion. If contaminants such as dirt or rainwater enter the radiator, it can easily lead to corrosion. 3. Radiator leakage. A leaking radiator can obstruct water circulation, and in severe cases, cause the radiator to "boil over." 4. Abnormal cooling fan speed. A damaged cooling fan or a short circuit in the wiring can cause the fan to stop working or rotate too slowly. Here are the solutions: 1. Immediately park the car on a flat and safe spot, preferably in a shaded area, without obstructing traffic. Place a safety warning sign 50 meters behind the car (150 meters on a highway). After noticing the boil-over, do not turn off the engine immediately; instead, let it idle. Turning off the engine at this point, when components are expanded and gaps are minimal, can cause some soft metals to detach and may even lead to engine seizure. 2. Keep the engine idling and open the hood to enhance heat dissipation. Once the temperature has dropped, refill the radiator with sufficient water. When adding water, use a damp towel as a pad. First, unscrew the radiator cap slightly to release steam, then fully open it after a short while. Never add water immediately when the radiator boils over, as the boiling water inside creates pressure. Opening the radiator cap right away can cause hot water to spray out, potentially scalding your face. Additionally, when the engine is overheated, avoid pouring cold water on it, as this can cause the engine block to crack due to sudden cooling, leading to irreparable damage.
When the car's radiator boils over and I see steam rising, I quickly pull over. This is usually caused by insufficient coolant or a system leak, and it could also be due to a clogged radiator or a faulty fan leading to poor heat dissipation. A stuck thermostat can also cause the temperature to skyrocket. Turning off the engine immediately is crucial—don't keep driving to avoid engine failure. Park in a safe spot and wait at least half an hour for it to cool down. Do not open the cap during this time to prevent burns. Afterward, check the coolant reservoir; if the level is low, add distilled water or coolant, but remember this is not a long-term solution. You must drive to a repair shop right away to check for leaks, replace the thermostat, or flush the system. Safety comes first—always monitor the temperature gauge while driving and don't be careless.
An overheated radiator is often caused by issues in the cooling system, such as a faulty water pump leading to poor circulation or a radiator clogged with dust. A non-functioning fan that fails to dissipate heat can also easily cause overheating. When handling this situation, the first step is to turn off the engine and park in a shaded area. After the car cools down, carefully open the radiator cap to check the fluid level—if it's too low, add water or coolant. Don't delay; take the car to a repair shop to check for leaks, fix the fan, or replace the thermostat. Regular maintenance, including checking the cleanliness of the coolant and ensuring the system is unobstructed, can reduce problems and provide peace of mind while driving.
