Can You Still Drive with a Bad Spark Plug?
2 Answers
You can still drive for a short time with a bad spark plug, but prolonged use without replacement can lead to aggravated engine damage or even total failure. Symptoms of a faulty spark plug include: 1. A layer of dark compounds covering the insulator skirt, electrodes, and shell; 2. The engine feels sluggish while driving; 3. Loud popping sounds or black smoke from the exhaust; 4. Rough idling and difficulty starting the vehicle; 5. Blackened exhaust pipes with unburned fuel discharge; 6. Regular engine shaking. Causes of a bad spark plug are: 1. Weak spark energy during ignition; 2. Excessively lean air-fuel mixture; 3. Overheating engine operation; 4. Clogged air filter; 5. High idle speed; 6. Severe carbon buildup and use of low-quality gasoline; 7. Damaged valve oil seals or crankcase ventilation valve.
As a veteran driver with years of experience, I must remind you: if your car's spark plugs fail, never force the vehicle to keep running. Last time, a friend of mine had a faulty spark plug—the car shuddered violently upon starting, and the engine ran like a hiccuping machine. After limping along for a few hundred meters, it stalled completely. Later, we discovered that running on a misfiring cylinder had even worn out the piston rings. Spark plugs ignite the air-fuel mixture in the cylinders—when one fails, that cylinder stops firing, causing instability, sluggish acceleration, a sharp spike in fuel consumption, and in severe cases, damage to engine components. My advice: pull over immediately for inspection. Don’t risk a hefty repair bill just to save on towing fees, not to mention the safety hazards or potential accidents. The key is to check spark plug lifespan during routine maintenance—most need replacement every 2-3 years. Don’t wait until trouble strikes to regret it.
