机动车在工作时发生故障常常会发出异声，通过正确的异声判断，找出故障，及时排除，就能防止事故，提高机动车的使用寿命。 　　机动车异声一般可采用金属杆或较大的螺丝刀来听诊。 1、活塞、缸筒敲击声 　　当发动机喷油泵供油时间过早或缸筒活塞磨损间隙增大时，在活塞上行 When a motor vehicle malfunctions, it often emits a different sound. By correctly judging the different sound, finding out the fault and timely eliminating it, it can prevent the accident and improve the service life of the motor vehicle. Different sound motor vehicles generally use metal rod or a larger screwdriver to auscultation. 1, the piston, cylinder percussion When the engine fuel injection pump premature or cylinder piston wear gap increases, the piston up