Does the spark plug work continuously or only during ignition?
3 Answers
Spark plugs work continuously as long as the engine is running. Working principle of spark plugs: The ground electrode of the spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the center electrode, it ionizes the medium between the center electrode and the ground electrode, generating a spark to ignite the air-fuel mixture in the cylinder. Spark plug replacement intervals: Under normal maintenance conditions, spark plugs should be replaced every 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine type, so it's recommended to follow the owner's manual. The following standards can serve as a reference for maintenance replacement: Platinum spark plugs should be replaced at 40,000 kilometers, standard nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers.
I've always been a car enthusiast and enjoy tinkering with my car's engine. Spark plugs don't work continuously; they only come into play during ignition. At startup, they provide a spark to get the engine running. Once the engine is operating, they fire precisely once during each compression cycle—otherwise, the gasoline wouldn't ignite. If they were constantly active, the battery would drain quickly, which would be such a waste. Spark plugs operate under high temperatures and pressure, making them prone to carbon buildup or wear. I recommend checking the electrode gap during routine maintenance and cleaning them thoroughly—don't wait until the car struggles to start before taking action. Having driven older models for years, I've encountered startup failures before, and replacing the spark plugs fixed the issue smoothly. These components work during engine ignition, not like a light that stays on all day.
I've driven various types of vehicles, from compact family cars to off-road SUVs. The spark plug doesn't work continuously—it only activates at the moment of ignition. During startup, it helps ignite the air-fuel mixture to get the engine running. Once the car is moving, it fires every few engine revolutions, adjusting based on RPM and load. Long-term neglect can lead to carbon buildup or widened gaps, potentially causing ignition failure, increased fuel consumption, or engine misfires. I make it a habit to inspect the spark plugs every 30,000 kilometers or so. They can be easily removed and cleaned with simple tools, saving money and ensuring peace of mind. The fact that spark plugs only work during ignition is easy to understand, and proper maintenance can significantly improve driving comfort.
