Under What Circumstances Should Car Spark Plugs Be Replaced?
2 Answers
Car spark plugs should be replaced under the following circumstances: when the top of the spark plug shows scars or damage, or when the electrode exhibits signs of melting or burning, these indicate that the spark plug is already damaged and should be replaced. During the replacement process, car owners can check for signs of burning and color changes in the spark plugs. Generally, resistance spark plugs should be replaced every 20,000 kilometers, platinum spark plugs every 40,000 kilometers, and iridium spark plugs every 60,000 to 80,000 kilometers. Spark plugs are crucial components of a gasoline engine's ignition system. They introduce high voltage into the combustion chamber and create a spark by jumping the electrode gap, thereby igniting the combustible mixture in the cylinder. A spark plug mainly consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell.
As a veteran driver with 15 years of experience, I've summarized some insights. If your car often takes two or three attempts to start in the morning, it's likely a sign of failing spark plugs. When overtaking on the highway feels sluggish—engine roaring but speed not increasing—that's another red flag. Black smoke from the exhaust coupled with high fuel consumption means it's time to check the spark plugs immediately. According to the maintenance manual, standard nickel alloy spark plugs need replacement at 30,000 km, while better iridium ones can last up to 80,000 km. Never exceed these intervals—last year, I tried saving money by extending their use by half a year, only to have the spark plug electrodes melt and destroy the catalytic converter. The repair cost me thousands, a classic case of being penny-wise but pound-foolish.
