Why does the radiator make a gurgling sound after the engine is turned off?

[LaIsabela]

This situation is normal. After the engine is turned off, some of the coolant flows back into the expansion tank. Since the temperature of the coolant is relatively high after shutdown, it is natural for the radiator to make a gurgling sound. Most engines used in cars are water-cooled, and water-cooled engines rely on the continuous circulation of coolant within the engine for heat dissipation. Two circulation paths: The coolant has two circulation paths within the engine: one is the major circulation, and the other is the minor circulation. Minor circulation: When the engine has just started, the coolant undergoes minor circulation. At this time, the coolant does not pass through the radiator for heat dissipation, which helps the engine warm up quickly. Major circulation: Once the engine reaches its normal operating temperature, the coolant undergoes major circulation. At this stage, the coolant passes through the radiator for heat dissipation, allowing the engine to maintain a reasonable operating temperature range. Coolant needs to be replaced regularly: If it is not replaced for a long time, it can lead to a decrease in the boiling point and an increase in the freezing point of the coolant. Such conditions can affect the normal operation of the engine. It is recommended to replace the engine coolant regularly. Moreover, each time the coolant is replaced, the old coolant in the cooling system must be completely drained before adding new coolant. When purchasing coolant: Always choose genuine products from reputable brands and ensure they are purchased through official channels. During regular vehicle use, it is essential to maintain your car on schedule.