What Causes the Boiling of the Expansion Tank Water?
2 Answers
The reasons for the boiling of the expansion tank water are as follows: 1. Malfunctioning cooling fan: A broken fan belt prevents the cooling fan from operating normally, drastically reducing its heat dissipation capability, causing the water temperature to rise until it boils. In such cases, it is necessary to promptly replace the cooling fan. 2. Radiator leakage: A leaking radiator affects its cooling capacity, leading to an increase in water temperature. Immediate inspection and repair at a service center are required. 3. Insufficient antifreeze in the radiator: When the antifreeze level in the radiator is below the normal range, the cooling capacity of the radiator decreases. It is essential to regularly check the antifreeze level and replenish it in a timely manner.
I just helped my neighbor check his car last week, and the boiling in the overflow tank was a major issue, usually caused by severe overheating in the cooling system. Insufficient or leaking coolant can prevent the engine heat from dissipating, causing the water to boil and bubble directly in the overflow tank. A clogged radiator or a broken water pump can disrupt water flow, leading to heat buildup. If the thermostat gets stuck and fails to open, it prevents coolant circulation, allowing hot water to flow back into the overflow tank. Additionally, if the fan isn’t working, this is more likely to happen when the car is stationary. Internal engine issues, such as a damaged cylinder head gasket allowing high-pressure gas to leak into the cooling system, can also cause a rapid rise in water temperature. I advised him to stop the car immediately, check the coolant level, top it up or replace the coolant, and visit a professional shop to identify the root cause to avoid engine damage and costly repairs. This can’t be delayed—overheating can burn out critical components, and the repair costs can be steep.
