Why does the car fail to start after washing?

[VanEliana]

The reasons why the car fails to start after washing: It may be due to the car getting damp, causing moisture in the area from the distributor to the high-voltage wire and spark plug, preventing high-voltage electricity from reaching the spark plug. You can open the distributor cover of the car and use a dry towel to wipe the damp areas. Alternatively, using a hairdryer to dry them can help the damp areas dry faster. Here are some precautions for car washing: 1. Avoid using water pressure that is too high: In professional car washes, the water gun is very particular. Generally, the water pressure should be between 4-7Mpa. If the water pressure is too low, it won’t clean properly, and if it’s too high, the water flow carrying paint surface dust may impact the paint layer, causing damage to the car paint. 2. Do not wash the car under direct sunlight: In fact, after rinsing the car body, water droplets on the car will form convex lenses, focusing sunlight on the car body, which over time will cause the car paint to lose its luster. The same goes for waxing; try to do it on cloudy days or indoors.

[Lima]

I've encountered the issue of the car not starting after washing several times, likely due to water seeping into the electrical system. The most common problem is moisture around the spark plugs or ignition coils—when they get wet, the circuit shorts out and the engine stalls. Another issue is the battery terminals; if water sprayed during washing isn't wiped dry, corrosion can lead to poor contact. Additionally, if the air filter accumulates water, restricted airflow can also prevent the engine from starting. Check these areas to ensure they're dry. If you spot any water traces, wipe them with a dry cloth or use a hairdryer. For prevention, avoid directly spraying high-pressure water into the engine bay during future washes, especially around the spark plug area. Safety first—if the car really won't start, don't force it. Take it to a professional repair shop to check the electrical system to avoid further damage.

[DiVivian]

It's quite common for my old car to fail to start after a wash. Looking back, the reasons mostly lie in moisture getting into electronic components—like corroded or loose battery terminals, or a tiny droplet of water near the spark plugs causing a short circuit. Sensors such as the crankshaft position or air flow sensors can also misread when damp, making the computer think the starting conditions aren't right. I remember that time when I used compressed air to dry out the ignition system and it worked. My advice is to start simple: check if any fuses are blown, ensure the battery terminals are tight and dry; then listen to the cranking sound—if there's noise but no start, it's usually a wet ignition system. Try waiting half an hour after washing before starting to avoid water accumulation.

[MacLaila]

Failure to start after car washing often stems from water short-circuiting the electronic system. Key components to check: wet spark plugs cause circuit breaks; moisture in ignition coils or high-voltage lines directly affects startup; un-dried battery terminals lead to corrosion; water ingress in sensors like oxygen sensors interferes with ECU decisions. Solutions: disconnect the battery for 10 minutes to reset the system, wipe dry any visible moisture. If there's a sparking sound but no response when starting, prioritize checking the ignition area; if silent, inspect the battery and starter. Prevention: ensure the engine cools before spraying water during washing, and wipe critical points afterward. Remember, addressing minor issues promptly ensures safety.