1.活塞敲缸的异响 （1）异响特征 异响的位置在机体的B-B区域（见附图）,是一种类似用小锤敲击水泥地面的有节奏的“嗒、嗒”声。柴油机在怠速低温时,声音明显且清晰;温度升高以后,声音减小以至消失;急加速时,声音更快、更响。 （2）故障原因 装配不当或磨损造成活塞与气缸的配合间隙过大;润滑不良,活塞和气缸壁直接相碰;个别连杆变形,造成活塞偏磨,间隙变大而敲缸。 （3）故障诊断 逐缸断油。如果给某缸断油时,声音明显地减小或者消失,而恢复供油时又可听到明显的“嗒、嗒”声,说明 1. Abnormal sound of piston knocking (1) Abnormal sound The location of abnormal sound is in the BB area of ​​the body (see attached figure), which is similar to the rhythmic clicking of a concrete floor with a small hammer . Diesel engine idling at low temperature, the sound is clear and clear; after the temperature increases, the sound decreases or even disappears; acute acceleration, the sound is faster and louder. (2) The cause of the malfunction improper assembly or wear caused by piston and cylinder with the gap is too large; poor lubrication, piston and cylinder wall directly collide; individual connecting rod deformation, resulting in partial piston wear, the gap becomes larger and hit the cylinder. (3) fault diagnosis by cylinder off oil. If you give a cylinder off the oil, the sound significantly reduced or disappeared, and the resumption of fuel supply and then hear the obvious “da, da” sound, that