Is There Water in the Exhaust Pipe in Winter?
2 Answers
In winter, there is water in the exhaust pipe because gasoline produces water and carbon dioxide after complete combustion. Here are the reasons why water dripping from a car's exhaust pipe is normal: 1. Correct air-fuel mixture ratio: When the vehicle's air-fuel mixture ratio is correct, water dripping from the exhaust pipe is normal. Whether it's an electronic fuel injection or carburetor engine, a correct air-fuel mixture ratio indicates that the vehicle's compression ratio is normal, and fuel consumption is within the normal range. 2. Normal engine cylinder pressure: When water drips normally from the vehicle's exhaust pipe, it indicates normal engine cylinder pressure, showing that there is no wear in the engine cylinder block and that all parts inside the engine are working properly. This method can be used to determine whether the fuel is burning normally. 3. Normal exhaust temperature: Normal water drainage from the vehicle's exhaust pipe also indicates that the exhaust temperature is normal, meaning the engine's power output is stable.
My old buddy in the garage has been drawing maps in the snow every day since winter arrived. Gasoline contains hydrogen, so burning it inevitably produces water vapor—just like how water droplets condense on a kettle lid. The higher the engine temperature, the more water vapor is generated, and since the tailpipe section is cooler, it naturally condenses into water droplets. This is especially noticeable during cold starts when thick white mist appears and dripping is most severe. But keep this in mind: if your car is gushing water in subzero winter temperatures, it might mean coolant is leaking into the combustion chamber—that’s when you need to rush to the shop to check the head gasket. My neighbor’s car had that issue last year and cost him 8,000 bucks to fix.
