What is the reason for the ceramic of a spark plug to be broken down?
2 Answers
The reason for the ceramic of a spark plug to be broken down is that the high-voltage electricity does not pass through the interior of the spark plug during the discharge process, but instead discharges directly to the iron shell of the spark plug, causing the external ceramic to be broken down. Working principle of a spark plug: Under the effect of high voltage, the air between the center electrode and the side electrode of the spark plug will rapidly undergo ionization, forming positively charged ions and negatively charged free electrons. When the voltage between the electrodes reaches a certain value, the number of ions and electrons in the gas increases like an avalanche, causing the air to lose its insulating properties, and a discharge channel forms in the gap, resulting in a "breakdown" phenomenon. At this point, the gas forms a luminous body, known as a "spark." Along with its thermal expansion, a "crackling" sound is also produced. The temperature of this electric spark can reach as high as 2000-3000°C, which is sufficient to ignite the air-fuel mixture in the combustion chamber of the cylinder. Criteria for judging spark plug damage: Spark plug damage may manifest in the following situations: difficulty starting, low power, excessive exhaust emissions, and increased fuel consumption. What is a spark plug composed of: A spark plug is mainly composed of a terminal nut, an insulator, a terminal stud, a center electrode, a side electrode, and a shell.
I've seen way too many cases of spark plug ceramic breakdowns, and it all boils down to extreme heat and pressure. Think about it - cylinder temperatures can soar over a thousand degrees during engine operation. No matter how tough the ceramic is, it can't withstand prolonged baking. And if the ignition coil acts up, causing a sudden voltage spike - bam! - instant ceramic failure. Just last month, my neighbor's car had this issue. When the mechanic opened it up, wow - carbon deposits had completely encased the spark plug, trapping heat until the ceramic cracked like a spiderweb. My advice? Regularly clean your throttle body, especially if you do lots of city driving. Traffic jams put extra strain on the engine, making this failure more likely. And don't cheap out on replacing worn spark plugs - saving a few hundred bucks now could lead to costly misfires and engine damage from ceramic failure later.
