What Causes Antifreeze to Boil Over?
2 Answers
The main reasons for antifreeze boiling over are the following five: 1. The radiator fan fails to operate. The inspection method is to directly turn on the vehicle's air conditioning cooling system. If the air conditioning compressor starts but the fan does not run, the fan must have malfunctioned. 2. Poor radiator cooling, which often occurs in April and May when there is a lot of willow catkins and cotton fluff. Inspection method: Open the engine hood and observe whether there is too much debris on the radiator. 3. If the coolant cannot circulate normally, it cannot perform its cooling function. If both the radiator and the return hose are at room temperature (normally they should be hot), the upper and lower hoses will become hard due to gas expansion inside the hoses. 4. The water pump belt may slip or idle if it has been used for too long. 5. High water temperature may be caused by a malfunctioning water temperature sensor or issues with the instrument panel or electrical circuit.
I've seen many cases of coolant boiling over, and the common causes include issues with the cooling system, such as a water pump not turning or being broken, which leads to poor coolant circulation and heat buildup. A clogged radiator with too much dust can also cause poor heat dissipation. If the coolant level is too low, it's prone to boiling. Additionally, a stuck thermostat that doesn't open when it should can cause the engine temperature to skyrocket. A failed pressure cap seal reduces pressure and lowers the boiling point. Air trapped in the system forming bubbles can also easily lead to boiling over. From my personal experience, this is most likely to happen in summer traffic jams. Once you see bubbles, you should immediately pull over, turn off the engine, and let it cool down. Failing to address it promptly can cause engine deformation or even total failure, leading to costly and labor-intensive repairs. Regularly check the coolant level and top it up with a reputable cleaning-type brand fluid if it's below the MAX line. Inspect the radiator and fan annually as a preventive measure.
