How long does it take to detect a steel wool in the exhaust pipe?
2 Answers
Steel wool stuffed in the exhaust pipe is easily detectable. If the exhaust pipe is blocked, the engine operation will be significantly affected, often causing it to stall immediately. If the exhaust pipe is blocked while the vehicle is parked, the car won't start at all, making it quickly noticeable. Below is relevant information: Exhaust backpressure: This refers to the pressure of exhaust gases as they pass through the exhaust system before being released into the atmosphere. If residual exhaust gases remain in the pipe, they create additional pressure for the next cycle of exhaust emissions. Combined with friction between the exhaust gases and the pipe walls, this results in higher pressure inside the exhaust pipe compared to atmospheric pressure—this difference is the exhaust backpressure value. At around 1,000 RPM, exhaust backpressure can reach approximately 35 kPa. For an exhaust pipe with a 10 cm diameter, the exhaust pressure inside can exceed 300 Newtons, which is more than enough to blow out the steel wool. Impact: If the steel wool gets stuck in the exhaust pipe and cannot be expelled, it can severely affect the vehicle. Blocked exhaust reduces the intake of fresh air, lowering the engine's air charging efficiency. This results in decreased power output and torque, leading to sluggish acceleration and engine vibration. Therefore, if you notice poor acceleration next time, it's advisable to check if the exhaust pipe is blocked.
If the exhaust pipe is stuffed with a steel wool ball, I can immediately notice something wrong as soon as I start the car. Because that thing blocks the exhaust outlet, the engine sound becomes extremely loud, almost like roaring. I remember once my car was pranked like this—just stepping on the accelerator resulted in a loud buzzing noise, and the power dropped noticeably. Even flooring the gas pedal couldn’t pick up speed. This kind of issue can be detected within minutes, especially during a cold start when the noise is louder and accompanied by slight smoke. Checking isn’t hard either—after turning off the engine, just look under the car to see if there’s any foreign object blocking the exhaust pipe, or if the engine sounds off, get it fixed right away. If you drive for too long before realizing it, the engine might overheat and damage the catalytic converter, leading to expensive repairs and even compromising driving safety. I recommend paying attention to your surroundings after parking to avoid such pranks, and never hand over your car keys casually.
