What are the symptoms of a faulty car ignition coil?
2 Answers
Symptoms of a faulty car ignition coil: 1. When idling, the car body shakes noticeably. You can observe the exhaust pipe outlet, where the exhaust gas flow shows obvious intermittency, and the exhaust pipe shakes severely with a clear popping sound; 2. While driving, when the engine speed is below 2500 RPM, the car body shakes noticeably with weak acceleration. The shaking disappears once the speed exceeds 2500 RPM; 3. Open the engine hood and observe the running engine. You will notice significant shaking that clearly deviates from the normal operating condition of the engine, with a large shaking amplitude.
Last month when my car wouldn't start, I discovered the ignition coil was faulty, with very obvious symptoms: repeatedly turning the key to start the car just wouldn't work, like it was struggling, and it barely managed to start after a long wait. The most annoying part while driving was the severe shaking, especially at idle or when accelerating—it felt like riding a broken motorcycle, with noticeably reduced power. Even climbing a gentle slope required stomping on the accelerator, and the car would still move sluggishly. The engine warning light inexplicably came on, and after cold starts, there was often a hissing noise. Later, on the highway, I noticed fuel consumption had surged by nearly 20%, and not only was there excessive black smoke from the exhaust, but tests also showed incomplete combustion. I felt this issue couldn't be delayed, as it could easily lead to bigger problems, so I promptly replaced the coil, and everything returned to normal. I suggest paying more attention to how the car starts and drives daily—don't wait until the problem worsens to fix it. After all, safety comes first.