What are the symptoms of water in spark plugs?
5 Answers
What are the manifestations of water in spark plugs? The engine may experience difficulty starting, insufficient power, stalling, and other symptoms. A spark plug is mainly composed of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell. Spark plugs are installed on the side or top of the engine. Early spark plugs were connected to the distributor via ignition cables, but over the past decade or so, engines in most cars have been modified to connect the ignition coil directly to 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 and forming a discharge channel, resulting in a "breakdown" phenomenon. At this point, the gas forms a luminous body, known as a "spark." Along with the 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.
Last month I drove to the countryside, and after the rain my car suddenly wouldn't start. At first I thought it was out of gas, but it turned out the spark plugs got wet. The symptoms were obvious: the engine wouldn't fire up at all when starting, making weird rattling noises while the car body jerked intermittently; when it barely started, acceleration was weak and it stalled several times like being held back. Later I noticed white smoke coming from the exhaust pipe, resembling water vapor. The mechanic said water corroded the spark plug electrodes and might even have damaged the cylinders. Now I'm extra cautious during rain and avoid directly spraying the engine bay when washing the car to prevent costly repairs. If you encounter similar issues, don't force it - get it checked immediately. Prevention is much easier than repair.
Having driven for over twenty years, I've encountered spark plug water intrusion issues a few times. The symptoms usually include difficulty starting, sputtering and misfiring during ignition as if it won't catch; sudden engine shaking or unexplained stalling while driving, with noticeably reduced power. In severe cases, thick white smoke from the exhaust pipe indicates water entering the combustion chamber. Water can short-circuit the spark plugs, damaging internal insulation materials; over time it corrodes the electrodes, affecting the entire ignition system. I recommend paying attention to moisture prevention in daily use—avoid driving fast through deep standing water; regularly replace spark plug seals or apply some waterproof glue; if any abnormalities are detected, stop immediately for inspection. Don't wait until the cylinder is ruined—that repair bill would be substantial.
As an ordinary office worker, I rely heavily on my car for daily commuting. The issue of water getting into the spark plugs is really annoying: symptoms include no response when starting or severe engine shaking after starting, as if it's gasping for breath; sometimes there's a lack of power during acceleration, feeling like the car could stall at any moment, especially more frequently on rainy days. This not only affects travel but also wastes time and money. Early detection is crucial—stop by the roadside and turn on hazard lights at the first sign; then find a professional repair shop for inspection and replacement. Additionally, avoid direct water jet from car wash guns onto the engine or driving through too much water, maintaining a dry environment can reduce the likelihood of occurrence.
I'm quite curious about car structures. Water entering the spark plug affects the entire ignition process. Symptoms include engine failure to start, intermittent misfires, or constant shaking; because water shorts the ignition gap, hindering arc generation. Unstable power output, white smoke from the exhaust pipe indicates water participating in combustion. Over time, the spark plug electrodes oxidize or crack, even affecting other components. Prevention is simple: don't let water near the spark plug holes, dry off after wading through water before driving; check the sealing condition every six months, clean dust with compressed air. Address issues promptly to avoid more faults.
