What are the common causes of a starter failing to start the engine?
1 Answers
There are several reasons why a starter may fail to start the engine: Severe wear of starter carbon brushes: When the starter carbon brushes are severely worn, the symptom during startup is weak starting power, and the crankshaft can be clearly seen turning very slowly through the belt and pulley. If the wear is extremely severe, the starter may not be able to rotate the crankshaft at all, producing only a buzzing sound of electric current. Fault in the starter control mechanism: In addition to the starter motor, the starter assembly also includes an electromagnetic control mechanism. The function of the electromagnetic control mechanism is to push the small pinion gear installed on the starter motor rotor outward to engage with the large ring gear on the flywheel, thereby allowing the starter motor to rotate the flywheel. When the control mechanism fails, the small pinion gear cannot engage with the large ring gear, naturally preventing the engine from starting. The symptom is that when turning the key to start, only the sound of the starter spinning at high speed is heard, without the sound of the engine crankshaft and flywheel operating. Damage to the starter clutch: There is also a clutch between the starter rotor and the gear. Generally, the starter operates at a speed of 120r/min, while the engine idles at around 900r/min after starting. The role of the clutch is to prevent the engine from driving the starter after startup, which could happen if the driver does not release the key in time, causing the small pinion gear and large ring gear to remain engaged, leading to the starter burning out. After the clutch is burned out, the rotor and small pinion gear will slip relative to each other, causing the engine crankshaft and flywheel to turn very slowly or not at all.
