Why is the car's acceleration sound loud?
3 Answers
Here are the reasons for loud acceleration sounds in cars: Noise only present during idle or low-speed operation: Causes of the noise include excessive clearance between piston and cylinder wall; overly tight piston pin or connecting rod bearing assembly; excessive clearance between tappet and its guide hole; wear on camshaft lobe profile; sometimes, loose starter clutch causing pulley noise (more noticeable during speed changes). Brief noise at certain RPM: Causes of the noise include cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive axial clearance of camshaft or loose camshaft bushing. Noise persists during high-speed operation: Causes of the noise include loose connecting rod bearing, melted or mismatched bearing shell rotation; loose crankshaft bearing or melted bearing shell; broken piston pin; broken crankshaft.
Once when I accelerated my car, the noise was unusually loud, with a buzzing sound that was quite alarming. The issue might be with the exhaust system—a damaged muffler or a leak in the piping can amplify the sound several times over, especially noticeable when climbing hills. The engine itself could also be suspect, such as aging spark plugs or a clogged air filter causing incomplete combustion of the air-fuel mixture, leading to a surge in noise. Additionally, worn-out drive belts or bearings can produce squeaky sounds, more pronounced at high speeds. It's advisable to start with simple checks, like looking for rust or cracks in the exhaust pipe, and to repair them promptly to avoid more serious engine damage that could affect driving safety. Regular maintenance, including periodic filter replacements and component inspections, can help prevent such issues.
I've been driving my own car for many years, and there are usually several situations when the acceleration sound becomes louder. Exhaust leaks are the most common, even a small hole can be noisy enough to sound like a roar; internal engine issues such as faulty ignition coils or insufficient engine oil can cause rough operation and noise; if it's a new car that has just had tires or suspension modified, imbalance and increased wind resistance can also amplify the sound; slipping or aging belts can also cause rattling noises. It's important to get it checked immediately and not ignore it. Last time I encountered a bad bearing, and when the sound was loud, fuel consumption also increased. I quickly went to the repair shop to check the wiring and sensors, and after fixing it, the car became much quieter.
