The engine system is a whole, which requires close cooperation of each component to meet the working needs of the engine; Any problem with one of these components will affect the normal operation of the engine. This issue of small rail brings you a case of “small problem” causing “big failure”.
The decoder is used to read the fault code, and no historical fault and current fault code are found; At the same time, when the driver reflects that the power is insufficient, the water temperature is too high.
After in-situ test run and reading the data flow, it is not found that the water temperature is high, the inlet pressure and inlet temperature are also displayed normally, and there is no problem with the multi state switch state; It shows that the lack of power is most likely caused by the driver’s heavy load and high water temperature. The next step is to follow the car to read the data flow of high water temperature.
When climbing with heavy load, read the data flow, the water temperature is 112 ℃, and the cooling water boils; Therefore, it can be determined that the reason for the lack of power is the high water temperature.
The main causes of high water temperature are: thermostat problems, radiator problems, fan problems and abnormal vehicle driving conditions of high water temperature.
After disassembly, let the driver go out for test run, and the fault remains the same of high water temperature.
Tips:
After removing the thermostat and allowing the cooling water to only go through the large circulation, it is necessary to block the inlet of the small circulation of cooling water to prevent the cooling water from going into the small circulation.
After installation and commissioning, the fault remains the same.
A new problem was found during the test run. When the temperature indication of the instrument is less than 100 ℃ (at the same time, the water temperature is 90 ℃), the coolant in the expansion tank is “boiling”.
Disassemble the engine and check the cylinder gasket.
Check the cylinder gasket and no abnormality is found; Next, check the copper sleeve of fuel injector.
Excessive scale will also affect the heat dissipation efficiency of the inner fins of the radiator and reduce the heat transfer capacity of the coolant and cold air. In this regard, the diesel engine cooling system should be cleaned regularly. At the same time, the use of inferior coolant should be avoided to reduce the formation of scale.
2. Non high water temperature turning over is generally caused by gas entering the cooling water channel. For this, our troubleshooting direction is as follows:
2.1 injector copper sleeve
There is cooling water around the copper sleeve of the fuel injector. When it is not tightly sealed, gas enters the water channel, resulting in the turnover of the expansion water tank
The high water temperature of the engine is actually because the “nose” is cracked!
2.2 air compressor
There is a cooling water channel inside the air compressor. In case of loose sealing inside the air compressor, the compressed gas will enter the cooling water channel and the expansion water tank will turn over.
The high water temperature of the engine is actually because the “nose” is cracked!
2.3 cylinder gasket
As mentioned in this case, I won’t go into too much detail here.
The high water temperature of the engine is actually because the “nose” is cracked!
2.4 cylinder head, cylinder block and cylinder liner
The expansion water tank cover mainly plays a role of pressure maintaining and ventilation. When the cover fails, it will be directly connected with the atmosphere, which will not have a great impact on the engine in general. However, in high altitude areas, due to the low air pressure, the engine coolant will boil at 80-90 ℃ and the expansion water tank will turn over.