Can Washing a Car Cause Water to Enter the Engine?

[NatalieLynn]

Washing a car will not cause water to enter the engine. During car washing or rain, the engine hood acts like an umbrella for the air intake. As long as water is not sprayed upward from below, it will not enter the area covered by the engine hood; instead, it will flow down from both sides and the rear of the hood. Water entering the engine can cause the following issues: 1. Engine stalling: After water enters the engine, the spark plugs cannot ignite, causing the car to stall while driving. 2. Failure to start after stalling: If water enters the distributor cap, it disrupts the normal ignition function, making the engine unable to start. 3. Engine damage or hydrolock: Due to the incompressibility of water, it can cause the connecting rods to bend or break, potentially piercing the engine block.

[Laila]

I've been driving for over a decade and washed my car hundreds of times, but I've never seen an engine get flooded. Normal car washes spray water on the body, not directly into the engine compartment. However, if you let the car washer blast high-pressure water directly at the wiring and sensors inside the engine, water might seep in through the seals. I know a friend who did just that, and the ignition coils got wet, making the car unable to start. So, it's best to remind them to use low-pressure water from a distance when washing, and for engine compartment cleaning, it's safer to use specialized cleaning agents. Some cars now have better-sealed engine compartments, but you still can't be too careful—repairing water damage can be quite costly.

[JosiahRose]

I was quite worried that washing the car might damage the engine, especially right after buying the car. Later, I specifically asked a mechanic, and he said it's completely fine as long as it's done properly. The engine compartment is designed to be waterproof against rain, so the water flow from washing is nothing to worry about. However, never spray water directly at the engine with a hose, as the high water pressure might damage the seals. When I wash my car myself, I usually avoid the computer module and the air filter intake, as getting water in these areas can cause trouble. Also, it's best not to rinse the engine when it's very hot, as sudden cooling might cause parts to deform. Usually, just wiping off the dust is enough; for a thorough cleaning, it's better to go to a professional detailing shop.

[BeauLee]

The issue of water entering the engine during car washing depends on the situation. During normal car washing, water only splashes onto the surface of the engine casing, as the underlying pipes and air intakes are designed with waterproofing in mind. However, modified cars are a different story. For example, cars with lowered suspensions or aftermarket mushroom air intakes have lower positions, making them more prone to water ingress. During my repair work, I've seen cases where owners used high-pressure water jets directly on battery terminals, causing water to flow along the wiring harness into the ECU circuit board. Therefore, when washing your car, pay attention to three things: do not remove the air filter to wash it, avoid spraying directly at sensors, and steer clear of power connectors. Extra caution is needed for older cars as their rubber components may have deteriorated.

[VanCorbin]

I used to wash my car casually, but later learned from forums that it might cause problems. Professional car washes first wait for the engine to cool down and then use low-pressure water mist, never blasting sensitive areas with high-pressure jets. Key areas to protect are water-sensitive components like the alternator and spark plugs. From my own experience, checking the air intake position is crucial—high-mounted designs are generally safe, but modified off-road vehicles with snorkels require extra caution. After washing, it's best to check for water marks around the dipstick and ensure the air filter box is dry. Regular maintenance includes replacing sealing gaskets frequently, as aged rubber compromises waterproofing.