Why Can't the Car Start After Washing?
3 Answers
After washing the car, the first thing to check is whether the air filter and carburetor have been exposed to water. If the air filter and carburetor are clean, the car should start. If there is no water in the air filter and carburetor, the issue is usually caused by water or moisture in the ignition circuit or electrical components. In this case, no repair is needed; the car can only start after being thoroughly dried. The water guns used in professional car washes are very particular. The water pressure for rinsing should be between 7 MPa. If the pressure is too low, the car won't be cleaned properly. If the pressure is too high, the paint layer may be damaged by the impact of water carrying sediment from the paint surface. The car washing process consists of several steps: preparation, fetching the car, washing, foaming, exterior cleaning, interior cleaning, and inspection.
After washing the car, it won't start, often because water flows into the engine compartment and causes a short circuit in the electrical system. Key components like the ignition coil and spark plugs can easily get wet, triggering the safety mechanism and preventing the car from starting. The battery terminals may also get wet and rust, leading to poor contact, or the air filter may become damp, causing abnormal air-fuel mixture and incorrect fuel injection by the engine. If a high-pressure water jet was used to spray directly into the electrical equipment area during washing, the risk is even greater. I've encountered this a few times—waiting about half an hour for the moisture to evaporate, then wiping the terminals clean and trying to start again. If it still doesn't work, check the fuse box for any blown fuses, and if necessary, take it to a repair shop to check if the ECU is damaged. When washing the car, it's best to avoid spraying high-pressure water onto sensitive mechanical areas or under the hood to prevent such issues. Be extra careful when washing the car yourself.
After washing the car, it suddenly won't start. The main risk is water seeping into the electrical system, damaging insulation and causing the ignition switch to short circuit, preventing startup. Water oxidation on the battery terminals can lead to unstable current, and a damp distributor can also cause ignition failure. When handling this, first disconnect the power to let the wiring dry. You can gently blow-dry sensitive areas or wipe connectors with a towel. Check if the fuse is blown and replace it with a new one. Some car models have fuse locations under the driver's seat, which are easily overlooked. If simple measures don't work, the relay or ECU module may be water-damaged and require professional repair. When washing the car, avoid spraying water vigorously into the engine bay, as high water pressure can cause more harm. Regularly checking the vehicle's sealing strips to prevent leaks is also crucial.
