What are the symptoms of faulty spark plugs?
1 Answers
Symptoms of faulty spark plugs include: Difficulty starting the engine, both during cold and warm starts, often requiring multiple attempts. Engine shaking or vibration while driving. Reduced power output, noticeably weaker performance than usual. Increased fuel consumption. Engine stalling. Failed emissions tests. Common causes and diagnosis of spark plug failures: Several factors can prevent spark plugs from functioning properly: Incorrect spark plug gap adjustment. A gap that's too small limits the contact area between the spark and fuel mixture while suppressing flame kernel growth, resulting in weak sparks. A gap that's too large may exceed the ignition system's voltage capacity. Cracked spark plug insulator. High-voltage current leaks through cracks, preventing proper sparking. Electrode carbon buildup causes current leakage around the center electrode instead of jumping to the side electrode. Excessive carbon can short-circuit the plug and damage the insulator. Electrode damage. Prolonged electrical erosion or chemical corrosion from combustion gases can break electrodes. Low insulation resistance reduces spark intensity or prevents sparking entirely. Short circuits in high-voltage wires. Leaks between the ignition coil and distributor prevent engine starting, while leaks between distributor and spark plugs affect individual cylinders. Burnt contact points in the distributor cause complete spark plug failure. Spark plug replacement procedure: Open the hood, remove plastic engine covers, and detach ignition wires (marking their positions). Remove old spark plugs using a socket wrench, cleaning any debris from the area. Hand-tighten new spark plugs before final tightening with the wrench. Reattach ignition wires in firing order and replace covers. Replacement interval: Typically 40,000-60,000 km under normal conditions, but varies by manufacturer and engine type (consult owner's manual).
