What Causes the Metallic Friction Sound When Pressing the Accelerator?
2 Answers
Pressing the accelerator and hearing a metallic friction sound is usually caused by carbon buildup in the intake system. It is recommended to visit a repair shop for cleaning. Below is an introduction to related car noise issues: 1. Car Half-Shaft Problem: Under long-term torsional fatigue and impact forces, the car's half-shaft is prone to bending, twisting, breaking, or wear and tear on the spline teeth. This can cause the car to shake rhythmically when accelerating within a certain speed range, accompanied by noise. The shaking disappears or lessens when the accelerator is released. 2. Loose Engine Belt: A slipping belt can produce abnormal noise. Once the belt slips, the resulting friction and heat can cause the belt to stretch further, worsening the slippage and creating a vicious cycle. In this case, it is necessary to visit a repair shop to adjust the belt.
I've been driving an old car for several years and often encounter a sharp metallic scraping noise when stepping on the accelerator, which is particularly annoying. Last time, I noticed it during a long-distance drive—the sound was like metal sheets scraping against each other. Possible causes include a loose or cracked exhaust pipe that expands and rubs under high temperatures, or worn-out belts in the drivetrain that make noise due to tension changes during acceleration. Continuing to drive like this poses significant risks, such as the exhaust pipe detaching and releasing hot air, compromising driving safety. I once tried a temporary fix by tightening the screws, but it didn’t last long—I eventually had to visit a repair shop to replace the parts for a permanent solution. With an aging car, part deterioration is common, so I recommend regularly checking the chassis and exhaust connection points to avoid cutting corners and risking bigger issues.
