What Are the Common Faults of Spark Plugs?
2 Answers
Common faults of spark plugs include: 1. Spark plug leakage; 2. Black deposits on the electrode; 3. Fracture at the top of the insulator; 4. Oil accumulation on the spark plug; 5. Spark plug erosion; 6. Excessive spark plug gap. The function of automotive spark plugs is to discharge the high-voltage pulse electricity delivered by the high-voltage wire, breaking down the air between the two electrodes to generate an electric spark, thereby igniting the mixed gas in the cylinder. Types of spark plug products: 1. Standard spark plugs: The insulator skirt is slightly recessed into the shell end face, with the side electrode outside the shell end face; 2. Insulator-protruding spark plugs: The insulator skirt is longer, protruding outside the shell end face.
Last time my car had issues, there were multiple spark plug failures. The most common problem was carbon buildup, with the ignition end covered in black soot, preventing the spark from jumping and causing slow engine starts and shaking. Next was incorrect electrode gap - too wide or too narrow both weakened the spark, making the car jerk while driving. Electrode wear is another chronic issue - prolonged use causes erosion and deformation, reducing ignition efficiency and skyrocketing fuel consumption. There's also oil contamination when leaks dirty the spark plugs in the combustion chamber, preventing ignition. More severe cases involve cracked spark plug bodies from overheating or impact. These faults often cause engine misfires, poor acceleration, and even damage engine components. I routinely inspect them every 20,000 km or as manual suggests - checking gaps, cleaning or replacing dirty ones promptly for worry-free and safe driving.
