The gold cup dual purpose passenger car is equipped with a large CA498 type turbocharged engine, and the blue smoke phenomenon occurs when the engine is speeding and accelerating. Fault check: check the oil pressure value, meet the requirements. Check the engine inlet, there are oil droplets in the pipeline, and it is preliminarily judged that the engine ("empty" cooling air) is caused by the oil of the supercharger leakage. Remove intake port of turbocharger and do not notice any abnormalities. Remove the exhaust connecting pipe, and there is a small amount of oil in the wall, thereby determining the fault is the failure of the oil seal of the exhaust turbocharger. After replacing 1 new turbochargers, the above fault occurs after running about 100km. Checking the turbocharger again found that there was still a small amount of oil in the exhaust pipe wall. The air filter was removed and the safety filter core was seriously blocked. Troubleshooting: after replacing the internal and external standard filter elements of the air cleaner, the engine is running normally, and the blue smoke will disappear and the trouble can be eliminated. Fault analysis: the air filter of the engine consists of a safe filter core and a main filter core, as the driver changes the main filter core that is about 5cm shorter than the standard filter core. The main task of the filter air is done by the safe filter core. In addition to the long time for the field operation, the working environment is bad, the safety filter core is blocked seriously, the air excess coefficient is reduced, the negative pressure is formed in the intake pipe of the exhaust gas turbocharger. When the engine works, the suction force of the intake stroke forces the lubricating oil to squeeze out from the oil seal and enter the engine through the air cooler. Airways, lubricating oil and fuel burn together in the combustion chamber, so the phenomenon of blue smoke appears at high speed.