What Causes the Metallic Friction Sound When Pressing the Accelerator?

[VonMarcus]

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.

[LiamMarie]

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.

[DelilahLynn]

As someone who enjoys DIY car repairs, I've encountered a metallic scraping sound when pressing the accelerator, resembling gears grinding. Potential issues could lie in the brake system—worn brake pads or rusted brake discs may cause friction noises. Alternatively, it might be loose wheel bearings creating friction sounds during rotation. When troubleshooting myself, I first rule out simple factors, such as checking for unusual noise sources near the tires. Always prioritize safety and avoid directly tampering with the engine. Additionally, the sound may become more noticeable when the engine is hot due to thermal expansion of components. If the issue persists, professional diagnostic tools should be used to prevent further damage. I recommend car owners regularly observe sound patterns, noting frequency and location for easier diagnosis.

[SanJulianna]

Every time I step on the accelerator and hear that screeching metal-on-metal sound, I get nervous, fearing serious car trouble. It might be caused by worn engine belts or rusted chassis components rubbing together, becoming louder under increased load during acceleration. If left unrepaired, it could lead to more severe failures, like damaging the transmission and causing loss of control. Last time I ignored it for a month, and the repair costs doubled. I recommend getting your car inspected immediately—safety first, never overlook these warning signs.

[Cavalcanti]

My modified car occasionally makes a metallic grinding noise when accelerating, sounding like something is being polished. For regular models, possible causes could be clutch slippage or a loose exhaust pipe connection; improper adjustment of the modified exhaust system can also amplify abnormal noises. You can try revving the engine in neutral to see if the noise persists. If it does, it's likely related to the engine. Be careful not to disassemble hot components on your own to prevent burns. It's recommended to take it to a workshop for a full inspection to ensure all moving parts are secure.