Why is there a gasoline smell when starting the car?
2 Answers
There is a gasoline smell when starting the car because the gasoline does not burn completely. When the car starts while cold, the onboard computer will appropriately increase the fuel injection based on the intake air temperature and coolant temperature signals. At this time, the engine has not yet reached its normal operating temperature, resulting in poor combustion efficiency. This causes some fuel to be expelled without being fully burned, hence the gasoline smell during a cold start. This situation is particularly common in winter. The normal operating temperature of the engine is between 80 to 90 degrees Celsius. Once the engine reaches this temperature, the onboard computer will correspondingly reduce the fuel injection. At the engine's normal operating temperature, the fuel will be fully burned, and the gasoline smell will disappear.
I've experienced the smell of gasoline after starting the car a few times. It's usually due to minor issues in the fuel system, such as a loose fuel tank cap causing fuel vapor leakage, or during cold starts when the engine needs to inject more fuel, making the smell more noticeable. More serious cases could involve aging or cracked fuel line connections, or damaged fuel pump seals leading to leaks. Never underestimate this issue—if there's any spark nearby, it could easily lead to a fire or explosion. Safety first: stop the car immediately and check underneath for any oil stains. Don't continue driving. When I worked as a mechanic, I saw many accidents caused by such small oversights. That's why I recommend getting it checked by a professional shop the same day, inspecting all connection points and the evaporative carbon canister system to ensure there are no hidden risks. Developing a habit of regular maintenance can prevent this from happening.
