一辆东风半挂车的 EQ140汽油发动机在怠速运转时排放蓝烟(该发动机已运行3万多公里),加速时更甚、更浓。对该发动机进行了如下修理:磨气门、更换气门导管和活塞环,又更换了曲轴箱通风单向阀均未能排除故障。原因究竟在哪里?发动机大量地排放蓝烟,毫 A Dongfeng semi-trailer EQ140 petrol engine emits blue smoke during idling (the engine has been operating more than 30,000 km), accelerating more and more concentrated. The engine was repaired as follows: the wear valve, the replacement of the valve guide and the piston ring, and the replacement of the crankcase ventilation check valve failed to remedy the problem. Where is the reason? The engine emits blue smoke in large quantities