Why does the engine make a gurgling sound like boiling water?

[StCaleb]

This phenomenon in the engine is related to the coolant. It may be caused by insufficient coolant or the use of low-quality coolant. This situation is more likely to occur in summer and is commonly referred to as "boiling over," which can affect the vehicle's performance and service life. When this happens, you can turn on the car's heater and set the temperature to the highest level for a few minutes before turning it off. Specific details are as follows: 1. Antifreeze: Antifreeze is produced by different manufacturers, and the freezing and boiling points vary by brand. Please consult the seller for specific information. Currently, the boiling point of antifreeze is generally above 105°C. If high-quality antifreeze is used, the "boiling over" phenomenon will not occur. 2. Freezing point of antifreeze: The freezing points of different antifreeze products vary, depending on the region and environmental temperature. Nowadays, the freezing point of antifreeze generally ranges between -15°C and -68°C.