What Causes the Coolant Reservoir to Keep Making Noise After the Car is Turned Off?
2 Answers
Possible reasons include a damaged radiator cap or insufficient antifreeze. Below is relevant information about coolant: Introduction: Used in automobiles, diesel locomotives, tractors, ships, engines, radiators, and various mechanical equipment, diesel and gasoline engines as a coolant in cooling systems. It has multiple functions such as antifreeze, anti-boil, anti-corrosion, and anti-scale. The boiling point of water is 100°C, while high-quality antifreeze coolant typically has a boiling point above 110°C, making it less prone to boiling over in summer compared to water. Reasons: The coolant reservoir cap is damaged, and the temperature inside the reservoir is very high. The coolant level exceeds the upper mark on the reservoir. A faulty thermostat causes the water temperature to rise too high, preventing the coolant from entering the engine's water passages for major circulation.
I remember that time when I was driving, after turning off the engine, the coolant reservoir kept making noise, which startled me. Later, I asked an experienced driver and learned that there might still be air in the system. After parking, the engine was still hot, and the air escaping from the reservoir created noise. Sometimes the fan was still running, and the vibrations transmitted to the reservoir could also cause noise. This isn’t a major issue, but you should check if the coolant level is too low. If the fluid is low, an empty reservoir is more likely to make noise. For regular maintenance, the cooling system needs periodic air bleeding to ensure the pipes are tight. If there’s persistent strange noise or the reservoir cap is leaking air, you must take it to a mechanic; otherwise, poor cooling could lead to engine overheating.
