汽车污染物来自排气管排出的废气、曲轴箱窜气和燃油蒸发等。
Automobile pollutants come from waste gases exhausted from outlet , blow-by of crankcase and vaporization of fuel .
摩托车主要排放源分为：曲轴箱窜气、汽油蒸发及排气管排放三部分；
Sources of motorcycle pollution are blow - by of crankcase , gasoline vaporization and emissions from exhaust pipe , i.
曲轴箱窜气