Why Does the Car Exhaust Pipe Make Abnormal Noises?

[DiCody]

Car exhaust bellows, also known as car exhaust flexible pipes, are installed in the exhaust pipe between the engine exhaust manifold and the muffler. They provide flexible connections for the entire exhaust system, thereby reducing vibration and noise, facilitating installation, and extending the lifespan of the exhaust muffler system. Below is an analysis of abnormal noises from the exhaust pipe: 1. Ignition timing too early or misfiring: Check the ignition timing. If the ignition timing is too early, it will advance the combustion pressure point, causing knocking. 2. Overly rich air-fuel mixture: An overly rich air-fuel mixture may result in incomplete combustion of the combustible mixture in the engine, which is then expelled with the exhaust gases. When this mixture encounters fresh air in the muffler, it reignites and produces explosive sounds. This phenomenon, known as backfiring in the muffler, manifests as heavy and unstable noises at low engine speeds but improves or even disappears at high speeds. 3. Excessive fuel level in the float chamber: A high fuel level in the float chamber not only leads to an overly rich air-fuel mixture but also allows some fuel to enter the cylinder without proper atomization. This unburned fuel is expelled with the exhaust gases and reignites in the muffler, causing backfiring. If large oil droplets are observed exiting the muffler or fuel continues to leak after the engine is shut off, it indicates an excessively high fuel level in the float chamber or a faulty float needle seal. In such cases, the carburetor should be cleaned or replaced.