Why is there an abnormal sound during cold start?

[CharlotteAnn]

Cold start with abnormal noise is generally caused by the loss of lubrication in the internal gears of the starter, resulting in stiffness and jamming, which affects the timely return of the gears. That is, when starting the engine, the starter rotates to drive the flywheel to rotate, thereby starting the engine. At this time, the engine speed is driven by the starter, so the engine speed is lower than the starter speed. When the engine speed after starting is higher than the starter speed, the ignition switch is manually turned off, and the starter is closed. Information about cold start is as follows: 1. A cold start is when the engine is started with low water temperature, usually after the car has not been started for a long time (such as after parking overnight). 2. Engine cold start refers to the situation where the engine is started after a period of time since the last shutdown, and its internal temperature is consistent with the ambient temperature.