What is the reason for the buzzing sound when stepping on the accelerator?
3 Answers
The reason for the buzzing sound when stepping on the accelerator is an inappropriate gear position, and it is necessary to downshift to increase speed. The accelerator, also known as the throttle or air valve, is a control device that regulates the engine's power (thrust). In piston-type aircraft engines, the throttle controls the opening of the carburetor's throttle valve to adjust the cylinder's filling volume, thereby determining the engine's output power. In gas turbine engines, the throttle regulates the metered fuel flow of the fuel regulator, thus determining the thrust generated by the engine. The throttle 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.
Last time I took my old buddy out for a drive, I heard a buzzing sound as soon as I stepped on the gas, which scared me into getting it checked right away. The mechanic said it was most likely an air leak in the intake system, possibly due to a cracked rubber hose from aging, causing the air to escape and create that buzzing noise. Another possibility is a rusted-through hole somewhere in the exhaust pipe, causing the exhaust to escape and resonate with the cabin. A common issue could also be worn-out rubber mounts on the engine supports, making the engine vibrate and buzz when under load. If these issues aren’t fixed in time, small problems can turn into bigger, costlier ones. That buzzing sound is like a mosquito—annoying and wasteful on fuel.
My car also made a buzzing noise when accelerating. The mechanic spent a long time under the car with a flashlight and found that the exhaust system resonator was damaged—it's specifically designed to eliminate exhaust noise. Additionally, if the belt in the engine bay is loose or the bearings are worn out, they tend to make noise when the throttle is under heavy load. If the driveshaft support bearing lacks lubrication and grinds dry, the sound will vary with the vehicle speed. Back then, I foolishly kept driving on the highway, and it ended up costing me over two thousand for repairs. My advice is to first note at which speed range the buzzing is most noticeable, so the mechanic can pinpoint the issue faster.
