某单位一台挖掘机在一次重点工程项目作业中出现发动机功率不足、冒黑烟、燃油和机油消耗升高的现象，司机确认系活塞缸套组磨损严重，导致窜气、窜油、功率下降，遂更换全部活塞缸套组，并更换机油，因工程紧急，更换后即投入全负荷使用。使用约90h后上述故障现象再次出现，停 A unit of an excavator in a key construction project operation engine power shortage, black smoke, fuel and oil consumption increased phenomenon, the driver confirmed that the Department of piston cylinder wear serious group, leading to channeling gas, channeling oil, power down , Then replace all the piston cylinder set, and replace the oil, due to the project emergency, after replacement into full load use. Use about 90h after the above symptoms again, stop