What is the reason for the ceramic of a spark plug to be broken down?

[TuckerLee]

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.

[SamanthaLynn]

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.

[SanVera]

Ceramic breakdown is mainly due to improper installation techniques. Some people change spark plugs themselves and apply excessive force when tightening, causing hidden damage to the ceramic body with a crack. Another issue is not installing the sealing washer, allowing gasoline to seep in and corrode the ceramic. I once saw a case at an auto repair shop where the owner bought cheap non-OEM spark plugs, and the poor-quality ceramic material got punctured by high-voltage electricity after just 3,000 kilometers. Actually, selecting spark plugs requires attention to the heat range rating—turbocharged cars need cold-type spark plugs, or else heat dissipation can't keep up. Another pitfall is using a high-pressure water jet directly on the engine bay during car washing; wet ceramic is especially prone to breakdown when electrified. It's recommended to drive about 100 kilometers after installing new spark plugs before hitting the highway, allowing the ceramic to fully adapt to the operating temperature.

[MadisonRose]

This issue commonly occurs in older or modified vehicles. Over time, the engine's valve stem seals deteriorate, allowing engine oil to seep into the combustion chamber and coat the spark plug's ceramic insulator, creating a conductive path. My friend's decade-old car had this exact problem – it emitted blue smoke during cold starts, and within two months, the spark plugs completely failed. Modified cars are even riskier; some enthusiasts flash the ECU for increased power, raising ignition voltage beyond what stock spark plugs can handle. Additionally, low-quality fuel additives leave chemical residues that degrade ceramic insulation. For prevention, inspect ignition coil resistance every 20,000 kilometers – values exceeding 5 kilohms warrant attention. White electrical erosion patterns on the ceramic indicate impending failure; never continue driving when these appear.