Can Water Enter the Engine Through the Spark Plug?

[VonAlexandra]

Under normal rainy conditions, water will not enter the spark plug of a car unless the rainfall is extremely heavy, reaching the level of the car's hood. In such cases, water can seep into the spark plug from under the hood. Spark plugs are installed on the side or top of the engine. In earlier models, spark plugs were connected to the distributor via ignition cables. However, over the past decade, most car engines have switched to direct connections between the ignition coil and the spark plug. Under high voltage, the air between the center electrode and the side electrode of the spark plug rapidly ionizes, forming positively charged ions and negatively charged free electrons. When the voltage between the electrodes reaches a certain level, the number of ions and electrons in the gas increases like an avalanche, causing the air to lose its insulating properties. A discharge channel forms in the gap, leading to a "breakdown" phenomenon. At this point, the gas becomes a luminous body, creating a "spark." Along with the heat expansion, a "crackling" sound is also produced. The temperature of this electrical spark can reach 2000–3000°C, which is sufficient to ignite the air-fuel mixture in the engine's combustion chamber.