What Causes the Rattling Sound from the Exhaust Pipe?
2 Answers
Here are the reasons for the abnormal noise from the exhaust pipe: 1. Damaged exhaust pipe: The engine exhaust emits high-temperature and high-pressure waste gases, along with some backfire explosions. Therefore, the exhaust pipe must perform silencing and purification. If the exhaust pipe is damaged (e.g., has a gap), waste gases will escape from the gap, causing a "rattling" sound. 2. Cylinder misfire: In multi-cylinder engines (most car engines are four-cylinder), the exhaust processes of each cylinder are interconnected. If a cylinder stops working, the exhaust sequence will be disrupted, leading to a "rattling" sound from the exhaust pipe. (If the misfiring cylinder fails to operate due to ignition issues, the unburned fuel-air mixture will explode and combust inside the exhaust pipe, resulting in a more intense rattling sound).
The exhaust pipe starts making a 'puttering' noise, just like my old car did a while back, especially noticeable at idle. The reason? It's mostly related to uneven engine operation, such as a problem with ignition in one of the cylinders where gasoline isn't burning completely, leading to irregular exhaust. It could also be due to a crack in the exhaust pipe or a leak at the joint, where air moving in and out creates that puttering sound. I found out the hard way that not addressing it promptly led to a sudden increase in fuel consumption and nearly caused the car to stall on the road. It cost me several hundred dollars to get it fixed. My advice: if you hear this sound, don't ignore it. Get to a repair shop as soon as possible to check the spark plugs or exhaust system. Also, paying attention to fuel cleanliness in daily use can help avoid such troubles.
