What Causes the Smell of Gasoline When Starting a Car?
1 Answers
Car starting with a gasoline smell is mainly due to the vehicle's catalytic converter, specifically the following situations: Cold start when the catalytic converter temperature is insufficient: The catalytic converter requires a working temperature between 200-350°C to start functioning, and during normal operation, the temperature should be between 350-700°C. During a cold engine start, the catalytic converter's temperature is low and hasn't reached the working temperature. Therefore, it is normal to smell gasoline in the engine exhaust. Under normal circumstances, the engine RPM is relatively high during a cold start, one of the purposes being to quickly raise the catalytic converter's temperature. Poor combustion condition when the engine is warm: Normally, after gasoline is completely burned and purified by the catalytic converter, no noticeable smell should be present in the exhaust. However, when the engine's combustion condition is poor, an incorrect air-fuel ratio can lead to incomplete combustion of some gasoline, resulting in a possible gasoline smell. This means that the main reason for the gasoline smell when the engine is warm is that some gasoline is not burned. Issues such as engine misfire, severe carbon buildup on spark plugs or fuel injectors, malfunctioning ignition system, inaccurate ignition timing, or a dirty oxygen sensor can all contribute to the gasoline smell. Aging catalytic converter: In many older cars, the catalytic converter may be severely aged, and the oxygen sensor heavily clogged, rendering it ineffective for purification. In such cases, a gasoline smell may also be detected in the exhaust. The solution is to replace the catalytic converter, as general cleaning is often ineffective.
