Why is there a metallic friction sound when pressing the accelerator?
4 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 are some related introductions about car abnormal noises: 1. Car half-shaft issue: The car's half-shaft, under long-term torsional fatigue and impact forces, is prone to bending, twisting, breaking, or wear and skewing of spline teeth. These faults can cause the car to shake rhythmically and produce noise when accelerating within a certain speed range, with the shaking disappearing or reducing after releasing the accelerator. 2. Engine belt looseness: A slipping belt will produce abnormal noises. Once the belt slips, it leads to friction and high temperatures, causing the belt to stretch further and worsen the slipping, creating a vicious cycle. In such cases, it is necessary to visit a repair shop to adjust the belt.
I've been driving for decades and have encountered the metallic friction sound when pressing the accelerator several times. The most common cause is wheel bearing wear. Since the bearing supports the entire wheel, over time or due to lack of lubrication, the metal components wear out. When you accelerate and the rotation speed increases, it produces that grinding metal sheet sound. This needs immediate attention, otherwise the wheel might seize up, which is extremely dangerous. I've faced this issue before and fortunately solved it by replacing the bearing in time. Additionally, similar sounds could come from the driveshaft or rusty brake discs, but bearing problems are the most frequent. I usually recommend regular maintenance and checking the vehicle's undercarriage to spot issues early. If you hear such noises, don't push your luck - get it checked at a repair shop immediately. Safety comes first.
My car has experienced this kind of metallic friction noise, especially when accelerating after starting in winter. It feels like metal scraping, and most of the time it's a brake system issue. If the brake pads don't fully retract or are slightly stuck, they can rub when accelerating. It could also be a small stone stuck in the chassis—I had this issue before, and the noise disappeared after removing it. This happens more easily on rainy days because parts are prone to rust and sticking. I suggest first checking around the wheels for any foreign objects yourself. If that doesn't help, have a professional shop inspect the brake discs and calipers. This can usually be done quickly, often within half a day, at a low cost. However, delaying repairs might lead to bigger faults affecting driving safety.
Every time I hear this kind of noise, I worry it might be a safety hazard, such as a damaged wheel hub bearing or an issue with the drive shaft. When accelerating by pressing the throttle, the friction increases, causing direct metal-to-metal contact. This indicates that the components may be aging or lacking lubrication. If not repaired promptly, the wear will worsen and could even lead to a loss of control accident. Therefore, when encountering this situation, I immediately slow down and stop to avoid the risks of high-speed driving. It's best to have a technician inspect it with diagnostic tools—don't wait for a minor issue to become a major one.
