What are the symptoms of a faulty ignition coil in a sedan?
3 Answers
Symptoms of a faulty ignition coil in a sedan include weak acceleration accompanied by shaking. Below is relevant information about ignition coils: Precautions: Avoid exposing the ignition coil to moisture or excessive heat. Do not turn on the ignition switch when the engine is not running. Regularly inspect and clean the ignition coil to prevent short circuits. There is no fixed replacement interval for the ignition coil; it does not need replacement as long as it functions properly. Generally, its service life exceeds 100,000 kilometers. Working Principle: The ignition coil, commonly referred to as the "high-voltage coil," is one of the core components of the ignition system in a gasoline engine. For the air-fuel mixture in the engine cylinder to combust, ignition energy is required. The ignition coil serves as the medium that provides this ignition energy, which is ultimately delivered through the spark plug to complete the ignition process.
Back when I drove older cars, it was quite common to encounter ignition coil failures. The car would suddenly shake like a tractor, especially noticeable during acceleration or uphill driving. Once on the highway, I stepped on the gas and felt the car lurching forward intermittently, with the tachometer needle jumping erratically. The worst part was black smoke pouring from the exhaust - when I pulled over, the fumes were choking, and the check engine light came on. The mechanic removed the spark plugs and confirmed the ignition coil had shorted, causing unstable firing voltage that led to incomplete combustion. Don't push your luck driving with this issue - you risk damaging the catalytic converter. Replacing it early is safer and more cost-effective.
If the ignition coil fails, the car will run very abnormally. The most obvious symptom is difficulty starting, requiring multiple key turns in the morning. When driving, it feels like someone is pulling you from behind, and the throttle response is sluggish. My friend's car had this issue—the mechanic used a diagnostic tool to read a P0300 trouble code. Upon removing the engine cover, they found the ignition coil for the third cylinder was cracked. After replacement, the shaking disappeared immediately, and fuel consumption dropped from 12L to 9L. Reminder: Pay attention to abnormal engine vibrations and observe exhaust smoke, as these are early signs of ignition coil failure.
