What Happens When Water Enters the Exhaust Pipe?
3 Answers
When a small amount of water enters the exhaust pipe, the accumulated water will gradually be expelled with the exhaust gases as the vehicle continues to be used, and it will not cause any noticeable adverse effects on the vehicle or the engine. However, if too much water enters, it can affect the engine, leading to stalling during operation. Waterlogged vehicles can be categorized into three scenarios: water submerging the exhaust pipe but not reaching half the wheel height, water just reaching half the wheel height, and water submerging more than half the wheel height. Generally, water just reaching half the wheel height can already affect the car. Water Submerging the Exhaust Pipe: If water only submerges the exhaust pipe, promptly moving the car away is sufficient. Water in the exhaust pipe will not be sucked back into the engine, and engine stalling is primarily caused by water entering the engine's intake system, unrelated to the exhaust pipe being submerged. Water Just Reaching Half the Wheel Height: If water just reaches half the wheel height, the car generally will not leak. However, if submerged for an extended period and the sealing strips have aged, the car may start to leak. In such cases, drive the car to a 4S shop, remove the interior trim, and clean and dry it. Water Submerging More Than Half the Wheel Height: If water submerges more than half the wheel height, the engine may take in water, and the interior may also leak. In this situation, never start the engine to avoid damaging the engine or interior electronic components. Additionally, if the car is waterlogged and starting it causes damage, insurance companies will not cover the repairs.
I had a terrible experience when driving through water and the exhaust pipe got flooded. Even a little water intake would make the engine sputter and cough, like it was choking. In mild cases, white smoke would come out, while in severe cases, the car would simply stall and refuse to move. If it's deep water, backflow can cause a water hammer effect, which is like hitting the engine internals with a hammer—leading to piston deformation, bent connecting rods, and repair costs starting from thousands of yuan. That time, I drove through knee-deep water, and the car stalled. It took a lot of effort to tow it to the repair shop. The mechanic said that having the exhaust pipe lower than the air intake is a safety hazard, and if the water level reaches halfway up the tires, you shouldn't force your way through. After water enters, don't rush to restart the engine; tow it first to avoid making things worse. Now, whenever I drive in heavy rain, I always keep a tow rope handy—just in case. Safety first.
When I'm driving, I often wonder, what happens if water gets into the exhaust pipe? It's actually quite simple. When driving through a puddle, water can enter the pipe. If the pressure is high, the water may block the exhaust pipe, preventing exhaust gases from escaping, causing the engine to suffocate and shake. In severe cases, if water enters the cylinders, it can damage the pistons like a bomb. That time when it was raining heavily, I drove through a small puddle and the car shook violently. I quickly pulled over, and when I checked, smoke was coming out. In the end, I spent several hundred dollars replacing parts. It's best not to let water rise above the midpoint of the wheels. Drive slowly through water, and if water does get in, don't start the engine in a hurry. Contact rescue services immediately to save money and trouble.
