What are the signs of a bad motor?
2 Answers
The signs of a bad motor are: 1. The car won't start, stalls at idle, sometimes it can start, and after starting, it can drive normally when accelerating; 2. Unstable idle speed, idle shaking; 3. The engine idle speed is too high; 4. The engine idle speed is too low; 5. Slow acceleration when speeding up, unable to run. The motor is used to bear the car's idle speed, its purpose is to adjust the idle speed according to the engine load at idle. The idle motor is installed on the throttle body and is controlled by the engine controller to regulate the engine idle speed. When the engine speed deviates from the idle speed, it is adjusted by the throttle valve, which controls the amount of air entering the intake manifold and is mechanically operated by the accelerator pedal cable.
After driving for so many years, I've noticed clear signs before a motor fails. The most obvious is when the engine responds sluggishly during startup. Turning the key often results in a dry clicking sound, but the car just won't start. If the battery is fully charged but the motor turns over weakly, sounding muffled as if it's starving, it's likely the motor's carbon brushes are nearly worn out. Once, I encountered a situation where the motor spun freely during startup, but the engine didn't budge—later, upon disassembly, I found the one-way clutch gear was slipping. When these signs appear, check the motor immediately; otherwise, it might fail completely at any moment, leaving you stranded on the roadside. Also, don't confuse this with a dead battery—a dead battery means all lights go out, while motor issues involve dashboard lights staying on but the engine refusing to start.
