What are the symptoms of mismatched spark plugs?
3 Answers
Symptoms of mismatched spark plugs include engine idle shaking, difficulty starting the engine, and lack of power during acceleration. Engine idle shaking: If the engine shakes while idling, it indicates a problem with the spark plugs, such as disconnected ignition wires or mismatched spark plugs during replacement. Difficulty starting the engine: If the engine requires multiple ignition attempts to start and stalls more frequently while idling, these are signs of mismatched spark plugs. Lack of power during acceleration and increased fuel consumption: Generally, after replacing spark plugs, the engine should run smoothly with strong acceleration and ample power, while also improving fuel efficiency. If the vehicle lacks power during acceleration and fuel consumption increases, it is likely due to an issue with the spark plugs.
Last time I tried to save money by buying cheap spark plugs online randomly, and the next day after installation, I found big problems! During cold starts, the engine shook like crazy, and when accelerating from a stop, there was a noticeable power lag. A few times during hard acceleration, I even heard the engine making cracking noises. On the highway, a yellow warning light suddenly popped up on the dashboard. The mechanic scanned it with a computer and said one ignition coil burned out due to mismatched spark plugs. The scariest part was the fuel consumption increased by 20%, and the exhaust had a weird sour smell. When we took them out, the electrodes of the new spark plugs were already burnt and deformed. I should’ve spent an extra 30 bucks to get the OEM ones!
Never randomly change the spark plug model. My friend's Hyundai Elantra once tried using the wrong heat range, causing sudden jerks around 1500 RPM like being yanked. At idle, the exhaust pipe made popping sounds, and the repair shop detected misfires in cylinder three. After driving 200 kilometers, the dashboard showed an emission system malfunction - definitely failing annual exhaust tests. The removed old spark plugs were completely covered in black carbon deposits. The mechanic warned that prolonged use would clog the catalytic converter, and replacing it would cost several thousand yuan.
