What Causes the Popping Sound from the Exhaust Pipe When Starting a Car?
2 Answers
Abnormal sounds from the exhaust pipe are mainly caused by an excessively rich or lean air-fuel mixture. The reasons for and solutions to abnormal sounds from a car's exhaust pipe are as follows: 1. Damaged exhaust pipe: The engine exhaust emits high-temperature and high-pressure exhaust gases, along with some backfire explosions. In this case, the exhaust pipe needs to be replaced immediately. 2. Engine misfire: In a multi-cylinder engine (most car engines are four-cylinder), the exhaust processes of each cylinder are interconnected. If one cylinder stops working, the exhaust sequence will be disrupted, causing abnormal sounds from the exhaust pipe. In this situation, professional repair personnel must be consulted for repairs.
I've been driving for over a decade and have experienced several instances of popping sounds from the exhaust pipe during startup. A common cause is water accumulation in the exhaust system—during winter or after frequent short trips in rainy seasons, condensed water fails to evaporate, and when the engine starts, it heats the water, producing popping sounds. Sometimes, the issue stems from loose exhaust pipe joints or cracks, where leaking exhaust causes a popping noise. It could also be due to carbon buildup obstructing airflow. I recall one inspection where a blocked drain hole was the culprit; clearing it eliminated the noise. Long-term neglect can lead to pipe corrosion or even affect the engine. It's advisable to check for dripping sounds or rust around the exhaust before starting; take longer drives to evaporate moisture; and maintain the exhaust system regularly, such as replacing hangers every six months to prevent detachment. While not urgent, early attention saves hassle and trouble.
