What are the symptoms of abnormal engine noise?

[TeaganLee]

Symptoms of abnormal engine noise include: 1. Piston slap noise; 2. Piston pin noise; 3. Crankshaft main bearing noise. Causes of abnormal engine noise are: 1. Cold start noise due to unsuitable engine oil; 2. Incorrect belt tension; 3. Poor fuel quality or incorrect fuel grade; 4. External engine factors; 5. Insufficient oil pressure preventing the timing chain from functioning properly; 6. Crankcase ventilation leakage. Solutions for abnormal engine noise include: 1. Check the fuel grade being used; 2. Inspect the engine temperature; 3. Examine the engine's air-fuel mixture ratio; 4. Verify the connection of the engine's negative ground wire; 5. Check for carbon buildup in the engine combustion chamber; 6. Inspect the ignition timing.

[SanRuby]

Engine abnormal noises come in various symptoms. A sudden "ticking" sound upon startup may indicate piston slapping against cylinder walls when cold; continuous "clicking" during acceleration could point to loose timing chains or bearing issues; persistent humming at idle might be caused by worn water pump belts or alternator problems; louder noises during turns or heavy loads resembling sharp metal friction sounds; some abnormal noises accompanied by resonance at high speeds are often mistaken for wind noise but actually signal internal component failures. Each symptom corresponds to different issues, and early detection can save major repair headaches. I make it a habit to monitor engine sounds while driving, promptly checking belt tension or listening to chain operation at the first sign of abnormality.

[AndresDella]

My old car recently had this issue. After starting, there was always an abnormal knocking sound under the hood, which became more noticeable when stepping on the accelerator, like something hard was hitting. It was also accompanied by a buzzing noise, especially when waiting at red lights. Once, there was a sudden "squealing" sound at startup, which scared me into turning it off immediately. A friend said these symptoms might indicate a loose belt, chain problem, or bearing wear, but without knowing the exact cause, the only option was to send it for repair. I suggest not taking any strange sounds lightly, especially if the noise increases as the engine temperature rises, as it could easily develop into a serious failure. Regularly changing the car's oil can also reduce the risk of abnormal noises.

[LaEvangeline]

Common symptoms of engine abnormal noise during driving include: harsh clicking sounds during cold starts, metallic knocking sounds during acceleration, and humming noises during steady-speed driving. These can be judged based on scenario changes—for example, humming may indicate belt system issues, while knocking could suggest enlarged piston clearance. Simple operations like turning the steering wheel or lightly pressing the accelerator can amplify the noise, aiding in problem localization. Regular attention can help avoid roadside breakdowns.