What Causes the Buzzing Noise in the Engine Compartment When Accelerating?
2 Answers
When the vehicle produces loud engine noise during acceleration, assuming you haven't shifted incorrectly or accelerated too abruptly, the following reasons may apply: 1. Transmission issues - the buzzing sound during acceleration isn't always from the engine; it could also be due to worn transmission bearings or insufficient lubrication fluid, causing friction. 2. Engine problems - observe if the RPM is excessively high. If the RPM increases during acceleration but the vehicle speed rises very slowly, the cause is likely clutch slippage, requiring replacement of the clutch kit. 3. Other issues - if noise occurs during steering, check for faults in the ball joints or power steering pump; if noise occurs during braking, the brake pads may be rusted or have debris due to water exposure; if noise occurs when the air conditioning is on, inspect whether the AC compressor pulley is slipping, etc.
I've encountered many similar situations when repairing cars. The most common cause of a buzzing sound during acceleration is resonance from a certain engine component, such as an improperly secured air filter box or a loose exhaust pipe bracket. Aging belts can also produce similar noises, especially when accelerating with the air conditioning on. Plastic guards in the engine compartment can deform over time and resonate with the engine at around 60 mph. There's also a hidden issue many people aren't aware of: if the turbocharger's intake pipe has a crack, it can produce a high-pitched whistle during hard acceleration, which sounds like a buzzing noise. I recommend first opening the hood to check for loose screws. The simplest method is to press your fist against the suspected loose part and have someone press the accelerator to see if the sound changes. If it's an electric fan malfunction, the fan will keep spinning erratically.
