What are the symptoms of a bad ignition coil?
2 Answers
Symptoms of a faulty ignition coil include: rough idling, poor acceleration, failure to start, noticeable intermittent exhaust flow, severe shaking of the exhaust pipe, and a strong gasoline smell in the exhaust. Ignition coils are categorized into open-magnetic and closed-magnetic types based on their magnetic circuits. Traditional ignition coils use an open-magnetic design, with their iron cores made of stacked silicon steel sheets about 0.3mm thick, around which the secondary and primary coils are wound. Closed-magnetic ignition coils feature a III-shaped iron core around which the primary coil is wound, followed by the secondary coil, forming a closed magnetic circuit. The advantages of closed-magnetic ignition coils include reduced magnetic leakage, minimal energy loss, and compact size, making them widely used in electronic ignition systems.
I've been driving this car for several years. Last time when the ignition coil failed, the engine started shaking violently, like sitting on a massage chair, especially during acceleration or climbing hills - it felt like the car had no power. At idle, the RPM kept jumping around, and I could hear strange noises even when stopped at red lights. Fuel consumption suddenly increased by about 15%, with one tank of gas covering 50 kilometers less. Black smoke started coming out too, which looked both polluting and wasteful. Starting became difficult as well, sometimes requiring several throttle presses to barely get it going. What's more annoying was that the check engine light on the dashboard kept flashing - that yellow warning light was really glaring. Later at the repair shop, the mechanic found it was misfiring caused by a failed ignition coil. After replacement, everything ran smoothly again. I'd suggest fixing it early, otherwise prolonged damage might affect spark plugs or the catalytic converter, leading to higher repair costs.
