Is it unsafe to drive a car that has taken in water?
3 Answers
Do not continue driving after the car has taken in water. If the vehicle stalls during water crossing, do not attempt to restart it. There are three possible scenarios if you restart the engine, detailed as follows: 1. Air filter gets wet: The car can still be driven, but with water entering the air filter, the engine will draw in some water vapor into the intake tract. This vapor mixes with gasoline and burns completely, causing minimal impact on the engine. 2. A small amount of water enters the engine: If a small amount of water enters the engine, it will mix with the engine oil, degrading its quality. Oil containing water increases wear on engine components, potentially leading to louder engine noise and vibrations in the future. 3. The engine restarts but stalls again after a few seconds: This is the most severe scenario. Since water cannot be compressed, when it enters the cylinders while the engine is running at high speed, the inability to compress water during the power stroke can directly cause bent valves and connecting rods, seized pistons, severe cylinder wear, and a bent crankshaft. In this case, replace the engine oil as soon as possible.
If your car gets flooded, I strongly advise against driving it. Water can seep into the engine and cause hydro-lock, leading to potentially exorbitant repair costs or even requiring a full engine replacement. There's also a high risk of electrical system short circuits—for instance, damaged control modules may cause instrument cluster failure, and sudden engine stalls while driving are extremely dangerous. I've seen a friend insist on driving a waterlogged car, only to end up with a ruined engine costing tens of thousands in repairs—a classic case of the cure being worse than the disease. The best course is to immediately turn off the engine, park in a safe location, and have it towed to a professional shop for inspection. Regular maintenance checks on seals can prevent this, especially before rainy seasons.
If I encounter a flooded car, I definitely won't risk driving it away. Technically speaking, water entering the engine intake can cause hydrolock, instantly damaging pistons and crankshafts. Electronic components like sensors and wiring will oxidize and short-circuit after being soaked, leading to more failures. Personal experience tells me that simple drying can only handle surface moisture, while residual dampness inside components will cause corrosion and rust, resulting in more subsequent issues. For safety, it's smarter to turn off the engine, call a tow truck for repairs, and simultaneously check the tire and brake systems to avoid collateral problems. This approach is much wiser than trying to save money on repairs.
