What Causes the Abnormal Noise During Cold Start?

[DiHayden]

The abnormal noise during cold start is usually caused by the loss of lubrication inside the starter's gears, leading to stiffness and jamming, which affects the timely return of the gears. Here are the relevant details: 1. When starting the engine, the starter motor rotates to drive the flywheel, thereby starting the engine. At this point, the engine's speed is driven by the starter, so the engine speed is lower than that of the starter. Once the engine starts and its speed exceeds that of the starter, manually turning off the ignition switch cuts the power, shutting down the starter. 2. Due to excessive dirt inside the starter and ineffective lubrication, the flywheel engine forcibly drives the starter to operate at its own speed. Since there is a speed difference between the two, this causes the abnormal noise heard from the starter. The noise only stops when the starter reaches the same temperature as the engine. However, in severe cases, the noise occurs every time the engine is started. To eliminate this noise, the starter must be cleaned and maintained or replaced.