Introduction to Automobile Engine Cooling System Maintenance

When a car engine is running continuously, its maximum combustion temperature may be as high as 2500 degrees. Even at idle or low speed, the average temperature of the combustion chamber is above 1000 degrees. Running at such high temperatures will accelerate the wear of the internal parts of the engine and also cause the oil to deteriorate. In order to ensure that the car engine can maintain a normal operating temperature, car manufacturers have installed a cooling system on the car engine.

The automobile engine cooling system is one of the six major systems of the engine. Its function is to dissipate part of the heat absorbed by the heated parts in a timely manner to ensure that the engine operates at the most suitable temperature.

Cooling system daily inspection

1. Check the water tank:

Normally, the water tank should have the same temperature at the top and bottom when the car is running. If one side is cold while the other side is hot, it means that the water tank is clogged. You can connect the water tank to a 2 kg pressure water pipe and flush it in reverse. If the blockage is serious, you can use a small amount of detergent. At the same time, pay attention to cleaning the dirt in the water tank and observe whether there is leakage.

2. Check the thermostat:

Some people think that removing the thermostat can prevent the water temperature from being too high. In fact, as long as the thermostat works normally, it will not cause the water temperature to be too high. It is also very harmful for the engine to run at low temperature for a long time. In addition, the thermostats of many engines are bidirectional. When the thermostat is closed, the cooling water is forced to go through the small loop, and when the thermostat is opened, the small loop is closed and the cooling water all goes through the large loop. If the thermostat is not installed, due to the throttling effect of the local resistance of the pipeline, very little water actually flows to the large loop, and the water temperature rises instead.

3. Check the water pump:

There are three ways that a water pump can be damaged: leakage, loss of rotation, and impeller corrosion.

The so-called loss of rotation means that the clearance between the water pump shaft and the impeller is too large. When the engine speed reaches a certain level, the water pump impeller cannot reach the corresponding speed, resulting in poor water circulation.

4. Check the fan

The fan is the main component of the cooling system. Some cars have eliminated the fixed fan and replaced it with an electromagnetic fan and a fan with a silicone oil clutch. Its characteristics are that the fan basically does not work when the car is cold, and the heat dissipation reaches the maximum when the car is hot; the main failure of the silicone oil fan clutch is oil leakage, while the main failure of the electromagnetic fan clutch is water temperature switch damage, circuit damage, and electromagnetic coil damage.

5. Check the exhaust system

In addition to using water as a heat dissipation medium, the engine can also dissipate some heat with the exhaust gas, and the engine oil can also take away some heat. The air convection around the engine plays an irreplaceable role. Therefore, when checking the engine overheating, do not forget to check whether the exhaust system (especially the models with catalytic converters) is smooth, and whether the engine oil and transmission oil cooling devices are intact. In addition, the air guide cover (commonly known as the wind circle) near the engine fan plays a vital role in the heat convection in the cabin, so you should pay attention to it when checking.

Cooling system maintenance standards

The cooling system of a car must be maintained after 2 years or 40,000 kilometers of use.

Five major standards for cooling system maintenance:

1. The coolant capacity is lower than the capacity line;

2. Coolant pH value ≤ 6;

3. The coolant is deteriorated and has scale;

4. The freezing point of the coolant is higher than -15℃;

5. The water temperature is high or boiling;

Whenever the above situations occur, cooling system maintenance is required.

Main points for cooling system maintenance

1. Check the sealing condition of the cooling system, the tightness of the fan belt, the sensitivity of the thermostat and the cooling water temperature, and make sure there is sufficient cooling water.

2. Clean the scale adhering to the cooling system including the radiator and water jacket to prevent the scale from affecting the heat dissipation performance of the cooling system.

Cooling system maintenance procedures

1. Preparation

Check whether the system has any mechanical or circuit failure. If so, repair it and then clean it; prepare the necessary products, equipment and tools.

2. Clean the cooling system

Empty the old antifreeze, fill with clean water, add water tank cleaner (RV3-35), and run at idle speed for 30 minutes; or directly add water tank cleaner (RV3-35) and run at idle speed for 30 minutes.

3. Replace the old liquid and add new liquid and water tank protective agent (RV3-36)

At idle speed, connect the equipment to the quick connector on the engine water tank and start the fluid replacement process. When changing the fluid, slightly increase the throttle and pay attention to the pressure gauge indication of the equipment. If the vibration is severe, increase the throttle a little more.

4. Restoration and completion work

After all the pipes are restored, run the car at idle speed, check the fluid level, and refill it. Check for leaks, and deliver the car only when everything is normal.