Spark plug failure manifests in the following ways: Difficulty in starting the car, both cold starts and warm starts become challenging, often requiring multiple ignition attempts. Engine shaking occurs, with noticeable vibrations during vehicle operation. Reduced driving power, with a significant feeling of insufficient power compared to normal conditions. Increased fuel consumption. Stalling incidents. Failure to meet exhaust emission standards. Common causes and diagnosis of spark plug failures: Several situations can lead to spark plug malfunction: Improper spark plug gap adjustment. A gap that is too small limits the contact area between the spark and the air-fuel mixture, and the flame quenching effect of the electrodes suppresses flame kernel growth, resulting in weak sparks and difficult mixture ignition despite sparking. A gap that is too large may prevent the ignition system from providing sufficient voltage to jump the gap between the electrodes. Cracked spark plug skirt. High-voltage current leaks through the crack, preventing sparking at the electrodes. Electrode carbon buildup, causing the center electrode to leak current to the surroundings instead of sparking to the side electrode. Excessive carbon deposits on the spark plug can short-circuit it, preventing sparking and burning out the insulator, damaging the spark plug. Electrode damage. Prolonged electrical erosion from sparks or chemical corrosion from combustion gases can cause electrode breakage or detachment, preventing sparking. Low insulation resistance of the spark plug. This reduces the ignition voltage applied to the spark gap, weakening the spark or completely disabling the ignition function. Short circuit in high-voltage wires. If the high-voltage ignition wire from the ignition coil to the distributor leaks, the entire engine may fail to start. If the wire from the distributor to the spark plug leaks, one cylinder's spark plug may not spark. Burnt platinum contacts. This can cause all spark plugs to fail to spark, preventing the engine from starting or running normally. Faulty spark plugs need to be replaced promptly. The replacement steps are as follows: Open the hood, lift the engine's plastic cover, remove the high-voltage wires, and mark each cylinder's position to avoid confusion. Use a spark plug socket to remove the spark plugs one by one, checking for external debris like leaves or dust and cleaning thoroughly. Place the new spark plug into the spark plug hole, hand-tighten it a few turns, then use the socket to tighten further. Reinstall the high-voltage wires in the firing order and secure the cover. Spark plug replacement interval: Replace every 40,000-60,000 kilometers under normal maintenance conditions, but this may vary by brand and engine type. Refer to the owner's manual for specific recommendations.
