What are the reasons for loud noise when stepping on the car accelerator?
2 Answers
Car accelerator noise is loud because: the engine loses power, and the internal valves of the engine are blocked. The accelerator, also known as the throttle or air valve, refers to the control device that regulates the engine's power (thrust). In piston-type aircraft engines, the accelerator controls the throttle opening of the carburetor to regulate the cylinder's filling amount, thereby determining the engine's output power. In gas turbine engines, the accelerator controls the metered fuel flow of the fuel regulator, thus determining the thrust generated by the engine. The accelerator position is controlled by the pilot in the cockpit through the throttle lever, which is transmitted to the carburetor or fuel regulator on the engine via control system components such as pushrods, rocker arms, torque tubes, cables, pulleys, and sector gears.
I've been driving for many years and encountered numerous situations with loud throttle noises. The most common issue is exhaust pipe leaks, such as loose weld joints or rusted-through spots, which produce an annoying buzzing sound. Another possibility is severe engine carbon buildup, leading to insufficient power and a crackling noise when accelerating, as if the car is protesting. Belt problems are also frequent culprits; for example, a worn or loose timing belt may produce a rattling noise during acceleration. If not addressed promptly, a snapped belt can destroy the engine. I've checked it myself several times—popping the hood to locate the noise source. Front-end noises often indicate belt or water pump bearing issues, while rear-end noises usually point to exhaust pipe problems. Regular maintenance is key: replacing the air filter or spark plugs might eliminate the noise. However, if it persists, don’t delay—visit a professional repair shop to avoid further damage.
