The radiator is one of the main working components of the engine's water cooling system. If the radiator is used for a long time, it will cause the core tubes to become clogged and the coolant to leak externally, resulting in an increase in engine temperature and affecting the normal operation of the engine. Therefore, we must learn the methods for checking and eliminating that fault. So, let's take a look at the common faults of engine radiators and their checks and eliminations together! 

The core tubes of the radiator are clogged. 
During low-speed operation of the engine, the coolant temperature is normal. However, during high-speed operation, the coolant temperature rises sharply. At this point, please focus on checking if the radiator is clogged. The reasons for radiator clogging include not only the presence of impurities in the original coolant, but also the mixed use of different brands of coolant, which can produce white crystals, easily blocking the narrow water channels inside the radiator and hindering the circulation of the cooling system, resulting in excessively high coolant temperature in the engine. 
1. Inspection for radiator blockage fault 
a. Measuring the temperature difference at the inlet and outlet of the engine radiator: Use an infrared thermometer to check if the coolant circuit of the engine radiator is blocked. The temperature at the water outlet of the engine radiator represents the temperature of the engine coolant, while the temperature at the return pipe is the temperature of the cooled coolant, which should be about 30 degrees lower than that of the outlet. If the temperature of the return pipe is too low, the radiator will cool down and the coolant will stop circulating. 
b. Observe the flow of coolant in the overflow pipe: After the engine reaches the temperature at which the thermostat opens, one person steps on the accelerator pedal while another person observes the flow rate of the coolant in the overflow pipe. When accelerating suddenly, a large amount of coolant from the radiator flows out through the overflow pipe, which can cause severe blockage of the radiator, increased resistance in the coolant flow, and failure to circulate properly in time. If the coolant path in the radiator is blocked, the working temperature of the engine will be too high, so the radiator needs to be cleaned. 
c) When there is space for inspection: An infrared thermometer can be used to measure the surface temperature of the radiator. If the temperature at the center of the radiator is higher than the ambient temperature, and the temperature at the bottom of the radiator is lower, it indicates that the water pipe at the bottom of the radiator is blocked. In this case, the radiator should be cleaned. 
d. Early wear of the water pump wheel: After the engine reaches the normal operating temperature, touch the upper and lower water pipes of the radiator with your hand. If the temperature of the radiator water pipe is low, it indicates that the thermostat cannot open and the thermostat must be replaced; if the temperature of the lower water pipe of the radiator is low, it indicates that the water pipe at the lower part of the radiator is blocked, and the plastic impeller of the water pump is damaged (modern engines mostly use plastic water pump wheels, and when the water pump wheel is worn, you can also hear abnormal sounds. Use an infrared thermometer to detect the radiator. For example, when the temperature in the middle of the radiator is high and the temperature around it is low, it indicates that the water pipe at the lower part of the radiator is blocked. Please clean the radiator. If the temperature in the center and the surrounding areas of the radiator is uniform, it means that the water pipe at the lower part of the radiator is not blocked, the fault is on the water pump wheel, and the worn water pump wheel must be replaced immediately. Many vehicle models stipulate that when replacing the synchronous belt, not only the tension pulley but also the water pump wheel must be replaced. 
e. Chemical reactions can corrode the water pipes of the radiator, causing the water pipes to become too soft. Electrochemical reactions are the reactions resulting from the substitution of the antifreeze in the coolant with the material of the water pipes. After the boundary between the coolant and the air pipe is grounded, the coolant will form a path to the grounded end, which may exacerbate the corrosion of the hose. When the fingers slip on the hose, if you find which part is very soft, it indicates that it has been corroded. Ground the negative side of the digital multimeter, add coolant to the positive side, and check the grounding condition when the voltage is above 0.3 V. When the grounding is poor, the grounding circuit uses the coolant as the grounding path, accelerating the corrosion of the radiator water pipes. 
The radiator needs to maintain a certain level of hardness. If the water pipes are too soft, they will be absorbed at high speeds, causing an increase in water resistance and hindering the circulation of the coolant. 
2. Elimination Method 
Chemical removal: Preparation of the cleaning solution. Firstly, 750 grams of caustic soda (soda ash) and 250 grams of kerosene are added to 10 liters of water; secondly, 700 to 1000 grams of caustic soda are added to 10 liters of water, along with 150 grams of kerosene. The former cleaning solution is used to clean cooling systems with strong corrosiveness and heavy scale, while the latter cleaning solution can be used to clean cooling systems with less corrosiveness and lighter scale. 
Before cleaning, add the original cooling water, remove the thermostat, and add the cleaning solution. Start the engine, run at medium speed for 5 to 10 minutes, then stop for 12 hours. Restart the engine, increase or decrease the speed, and use the water's impact to make the scale and other deposits float. Run for 10 to 15 minutes and then stop. Release the cleaning solution while it is still hot. After the engine cools slightly, add clean water and run at medium speed for 4 to 5 minutes to allow the water to circulate. Repeat this process 2 to 3 times and check the discharged water until it becomes clean. Finally, install the thermostat and add clean cooling water. 
The above content covers the common fault checks and troubleshooting for engine radiators. If you want to know more, please feel free to contact us at any time!