What are the symptoms of faulty car spark plugs?
3 Answers
The symptoms of faulty car spark plugs are: 1. Causes the engine to produce a large amount of carbon deposits; 2. Difficulty in starting the car; 3. Excessive exhaust emissions; 4. Insufficient power; 5. Black smoke from the exhaust pipe; 6. Rough idling; 7. Electrode melting and insulator turning white; 8. Electrode rounding and insulator scarring. The causes of faulty car spark plugs are: 1. Severe carbon deposits or oil contamination on the spark plugs; 2. Mismatched spark plug model; 3. Long-term idling operation of the engine; 4. Cracked insulator skirt of the spark plug; 5. Excessive spark plug gap; 6. Low insulation resistance of the spark plug; 7. Short circuit in the high-voltage wire.
As a seasoned driver with years of experience, I can tell you that when spark plugs go bad, the symptoms are quite noticeable. The engine struggles to start, often requiring multiple attempts to ignite, especially in winter when it's even more troublesome, sometimes accompanied by a rattling noise. At idle, the car shakes like sitting on a rocking chair, unstable, and when stopping at a red light, the entire body vibrates uncomfortably. Acceleration becomes sluggish, with a delayed response when pressing the throttle, and there's a noticeable lack of power when going uphill. Fuel consumption also spikes, often burning an extra 1-2 liters per 100 kilometers. The engine may even misfire, causing irregular engine sounds and occasional clicking noises. In more severe cases, the dashboard warning light will come on. If spark plug issues aren't addressed promptly, incomplete combustion can occur, potentially damaging the catalytic converter. It's recommended to check the spark plugs every 20,000-30,000 kilometers, focusing on the gap and carbon buildup, to ensure optimal performance and safety.
As a relatively young car novice, I recently experienced spark plug issues firsthand. Initially, there were ignition abnormalities—the engine would groan during startup but fail to fire up, which made me quite nervous. At idle, the car noticeably shook, and the vibrations while stopped at red lights were downright embarrassing. Acceleration felt sluggish, power lagged when overtaking, and fuel consumption quietly increased—where a full tank used to last 500 km, now it falls far short. Later, diagnostics revealed carbon buildup on the spark plugs caused poor sparking, delaying ignition timing. Delaying repairs could also trigger the emissions light or engine misfires. Learned a tip: During routine maintenance, ask the mechanic to check spark plug gaps with a diagnostic tool—replacement is typically needed every 40,000 km or so. Also, spark plug types like copper or iridium affect lifespan and performance, and matching the right heat range can prevent issues. Keeping the ignition system in good shape ensures a more worry-free drive.
