What Causes a Car Motor to Fail?

[TeaganLee]

There are several reasons why a car motor may fail: 1. Severe wear of the starter carbon brushes: The carbon brushes are responsible for delivering current to the rotor, causing it to rotate. Although the starter only operates during startup and works for just a few seconds, the current during operation can reach several hundred amperes. 2. Carbon brushes pressing against the rotor: Under the preload force of the spring, the carbon brushes press tightly against the rotor. At the moment of startup, strong electrical sparks are generated at the contact points between the carbon brushes and the rotor, leading to carbon brush erosion. 3. Severe belt wear: Through the belt and pulley, it is evident that the crankshaft rotates very slowly. When the wear is extremely severe, the starter may not be able to drive the crankshaft to rotate at all, producing only a humming current sound.