What is the buzzing sound when stepping on the accelerator?

[ElliottLynn]

Buzzing sound is the friction noise of components during engine operation. Main causes: Lack of engine oil inside the engine; Engine oil not changed for a long time; Engine oil viscosity too low. The following are the main functions of engine oil: 1. Lubrication and friction reduction: There is rapid relative sliding between pistons and cylinders, as well as between main shafts and bearing bushes. To prevent excessive wear of parts, an oil film needs to be established between the two sliding surfaces. A sufficiently thick oil film separates the surfaces of relatively sliding parts, thereby achieving the purpose of reducing wear. 2. Cooling: Engine oil can bring heat back to the oil tank and then dissipate it into the air to help the radiator cool the engine. Good engine oil can bring carbon deposits, sludge, and worn metal particles on engine parts back to the oil tank through circulation, and flush away dirt generated on the working surfaces of components through the flow of lubricating oil.

[LaHayden]

I've been driving for nearly thirty years, and I've encountered throttle buzzing sounds quite often. This kind of noise usually occurs between 1500 and 3000 RPM and is typically caused by mechanical component resonance. The most common cause is the aging of engine mount rubber, which loses its damping effect, allowing engine vibrations to directly transfer to the frame. Another possibility is an air intake pipe leak, especially in older cars where pipe joints are prone to cracking and leaking. Damage to the front exhaust pipe gasket can also produce a low-frequency buzzing sound during acceleration. Additionally, wheel bearing wear to this extent can produce similar noise, but the difference is that bearing noise changes with vehicle speed, while throttle noise changes with engine RPM. I suggest you first try revving the engine in neutral to listen for sound changes, as this can help preliminarily determine whether it's an engine issue or a drivetrain problem.

[MartinFitz]

Last week my car also made this annoying buzzing sound when accelerating. Had a mechanic check it and turns out the exhaust pipe gasket had aged. Replaced the gasket and it quieted down. This type of noise is mostly vibration-induced, possible locations include the belt tensioner pulley bearing in the engine bay, power steering pump bracket, or loose exhaust pipe hangers. I later discovered that a deformed cooling fan shroud touching the blades can also cause resonance at specific RPMs. Suggest you note the exact RPM range when the noise occurs, whether there's difference between cold and warm engine, and if the sound appears when revving in neutral. These details help mechanics diagnose faster. Address issues early - if an exhaust hanger completely breaks, it could drag and get damaged.

[KingstonFitz]

Buddy, I just solved this issue recently! The buzzing sound during acceleration is most likely due to an exhaust system leak. Especially in turbocharged cars, it could be a leaking intercooler pipe or loose exhaust pipe connections. Another possibility is the intake system, like an improperly installed cone air filter or loose intake pipe clamps. Modified exhaust systems are particularly prone to this kind of resonance noise. Quick self-check: When the engine is cold, open the hood and have someone rev the engine while you feel around the exhaust and intake pipe joints for leaks. Just remember to stay safe and keep away from the fan. Bearing issues could also be the culprit, but that kind of buzzing noise is more related to vehicle speed. In most cases, replacing an exhaust gasket or tightening a clamp will fix it.

[SanJace]

I also experienced a buzzing noise during acceleration, which was particularly unsettling. Later, I took it to a repair shop and found out that the right engine mount had sunk. After the repair, the noise completely disappeared. This type of sound often occurs in the mid-to-low engine RPM range, especially noticeable when climbing hills. Common causes include loose bolts on the power steering pump bracket or resonance from the engine undercover. Another easily overlooked issue is the detachment of the firewall sound insulation, which allows vibrations to directly transmit into the cabin. As regular car owners, we can simply check for any signs of undercarriage scraping and inspect whether the rubber on the engine bay mounts has cracked. Since it involves driving safety, it's recommended to consult a professional technician as soon as possible. They can quickly pinpoint the source of the noise using a stethoscope.