Can a Car Still Run if the Exhaust Pipe is Flooded?

[DelMolly]

After being flooded, a car can still run with water in the exhaust pipe. Below are precautions for driving in rainy weather: Check the wipers: Especially important for nighttime driving during heavy rain. Maintain distance: Control your speed. Roads become slippery when wet, reducing tire traction. If driving too fast, inertia increases, and braking effectiveness significantly decreases in emergencies, raising the risk of accidents. Avoid sudden maneuvers when encountering water: If you see water and immediately swerve or brake sharply, the vehicle behind may not react in time, increasing the chance of an accident. Estimate the water depth; normally, if it's under 15 cm, you can drive at regular speed. When crossing water, control the throttle and avoid stomping on it suddenly, which could overload the engine or cause tire slippage.

[ArcherRose]

I've been driving for decades and always take extra caution on rainy days. A couple of summers ago during a heavy downpour, my young neighbor drove through deep water with his exhaust pipe submerged, stubbornly pushing forward until his engine stalled on the spot. When towed to the repair shop and opened up, all three connecting rods in the cylinders were bent. Think about it - when water enters the exhaust pipe, the engine trying to expel exhaust is like someone covering its mouth and nose. Forcing it to run causes water to backflow into the cylinders. When pistons try to compress water (which is incompressible), it directly damages internal engine components. So whenever you see the exhaust pipe submerged, the wisest move is to immediately turn off the engine and stop. Don't hesitate to call for a tow truck - that's the right thing to do.

[AllieLee]

I've seen too many flood-damaged cars in the repair shop. Vehicles that continue driving with water in the exhaust pipe almost always end up needing major repairs. Once water submerges the exhaust pipe, it means the exhaust system is water-sealed, and exhaust gases can't escape, leading to backflow. The most dangerous scenario is when the engine is running, and water flows back from the exhaust pipe into the cylinders. The impact force generated by the piston compressing liquid water can directly bend the connecting rods. During my repairs, I've found that fixing such damage often costs tens of thousands. In such situations, the correct approach is to immediately turn off the engine and cut the power. Remember, never attempt to restart the engine, or the insurance might refuse the claim. It's best to have the car towed by professionals to a repair shop, where the spark plugs need to be removed to check if water has entered the cylinders.

[VonVivienne]

Last time I drove to the suburbs and encountered a heavy rainstorm. When passing under a bridge, the water level suddenly rose, and I was terrified to see bubbles gurgling from the exhaust pipe. I immediately shifted to neutral, held the brake, and watched helplessly as the water reached the exhaust pipe outlet before decisively turning off the engine and waiting for rescue in the car. The mechanic later told me that if the engine is still running when the exhaust pipe is submerged, the high-speed pistons can suck water back into the cylinders. It's like stuffing mud into a working water pump—best-case scenario, the engine stalls; worst-case, the entire engine is ruined. Thankfully, I didn’t foolishly step on the gas, or my car, which I had just bought six months prior, would have needed major repairs. Now, whenever I encounter flooded areas, I detour in advance. If I can’t avoid it, I stop to assess—if the water level exceeds half the tire height, I absolutely refuse to move the car.

[Pluto]

As a driving instructor, I often remind my students: the exhaust pipe is the lifeline when driving through water. If the exhaust pipe is submerged and the vehicle continues to move, not only will the engine stall immediately, but more dangerously, water can instantly flood into the cylinders, causing the piston connecting rods to deform or break. I've personally seen engines in repair shops with damaged cylinders—repair costs can be high enough to buy a used car. The correct handling principle is the 'double stop, double open' method: stop the engine, stop moving forward, open the windows to assess the situation, and turn on the hazard lights. Most importantly, never attempt to restart the engine—water won't drain out just because you restart the car. It's advisable to keep the insurance company's rescue number handy and call for a tow truck immediately in such situations to avoid further damage.