Can the Car Start if Water Enters the Exhaust Pipe?
2 Answers
Automobile exhaust pipes are devices installed between the engine exhaust manifold and the muffler to reduce vibration and noise, facilitate installation, and prolong the life of the exhaust silencing system. They allow the entire exhaust system to have flexible connections. Whether a car can start if water enters the exhaust pipe depends on the amount of water that has entered, which can be divided into the following two scenarios: 1. Small amount of water entry, the car can start: Typically, the wading height for cars is in the range of 50-70 centimeters, and the position of the exhaust manifold is similar in height to the intake manifold. 2. Large amount of water entry, the car cannot start: The end of the exhaust pipe has a muffler. If a large amount of water enters (such as during reverse flow when wading or when water seeps in while parked in a low-lying area with the engine off), it can accumulate in some dead corners of the muffler, eventually leading to rust and perforation.
Water entering the exhaust pipe indeed prevents the car from starting, which is a common yet dangerous situation. Having driven for decades, I've personally encountered similar issues. If water gets into the exhaust pipe, such as after driving through a deep puddle and stopping, never rush to start the engine. Water in the exhaust pipe can be sucked back into the cylinders during startup due to the engine's suction force, causing a hydraulic lock (water hammer effect). Since water cannot be compressed, the sudden pressure can damage pistons or connecting rods. This not only prevents the car from starting but may also lead to complete engine failure, with repair costs ranging from thousands to tens of thousands. For safety, immediately turn off the ignition if water ingress is detected and arrange for towing to a professional repair shop. They will drain the water and check for engine damage. The key to prevention is avoiding deep water while driving and always observing road conditions.
