
Engine cooling systems can be divided into two types: water-cooled and air-cooled. Modern vehicles widely adopt water-cooled systems, which mainly consist of the following components: 1. Radiator and cooling fan. 2. Water pump and thermostat. 3. Water jacket and hoses. 4. Coolant expansion tank, coolant temperature gauge, coolant temperature sensor, etc. Below are the functions of an automotive cooling system: 1. Maintain the engine within an appropriate temperature range under all operating conditions. 2. Dissipate heat transferred to the engine during fuel combustion to prevent high-temperature damage to related engine components. 3. Absorb partial heat from heated parts and then transfer it to the vehicle's heat dissipation device, where air-liquid cooling dissipates the heat into the atmosphere.

With over a decade of car repair experience, I've found that the cooling system boils down to these key components: The most visible is the radiator, responsible for heat dissipation. The water pump acts like a heart, circulating coolant through the engine's water passages. The thermostat opens and closes with temperature to regulate flow - if your heater is slow in winter, it's likely the culprit. The cooling fan sits behind the radiator and spins aggressively during traffic jams or AC use. The expansion tank stores excess coolant, and low levels are problematic. Metal and rubber hoses connect the entire system, with aged rubber hoses being the most common leak source in older vehicles. Don't underestimate coolant's corrosiveness - it must be replaced every two years. I've encountered several cases where corroded water pump impellers seized up.

That day, I helped the neighbor's younger sister check her broken-down car and found that the coolant had completely leaked out. I explained to her that the system is like the human blood circulation: the engine water passages are equivalent to blood vessels, with water channels running through the aluminum cylinder block; the radiator is like the lungs, responsible for heat dissipation; the thermostat acts as a temperature regulator; and the water pump provides the power for circulation. I also reminded her to keep an eye on the dashboard's temperature gauge—if the needle exceeds 90 degrees, she should be alert. Additionally, I taught her to check the pink/green antifreeze level every month and to top it up immediately if it falls below the MIN line.

All car modification enthusiasts know that the stock cooling system can't handle aggressive driving. We upgrade to larger aluminum radiators, install high-flow water pumps, and use silicone hoses for better high-temperature resistance. Turbocharged cars must have oil coolers to share the heat dissipation load. Once at a track day, I saw someone wrap their hoses with heat-reflective silver foil and even replace the radiator fan with a dual-fan setup. But a word of caution for beginners: don't randomly install aftermarket thermostats—incorrect opening angles can cause abnormal water temperatures.


