What Causes Engine Abnormal Noise During Rapid Acceleration?
2 Answers
Engine abnormal noise during rapid acceleration may be caused by excessive carbon buildup in the throttle valve, piston slap, or bearing aging. Excessive carbon buildup in the throttle valve: Excessive engine carbon deposits can cause idle rotation, lead to gear wear, and trigger abnormal noises. Regular cleaning of engine carbon deposits, throttle valve cleaning, and spark plug replacement are recommended. Piston slap: Improper piston profile design, excessive cylinder clearance, combined with the back-and-forth swinging of the contact surface between the piston and cylinder, can produce piston slap sounds against the cylinder wall. Regular oil changes are necessary to maintain good lubrication. Bearing aging: The engine is surrounded by transmission bearings, and prolonged driving can cause severe bearing wear, resulting in excessive clearance and abnormal noise. Regular maintenance should include inspection and replacement of aged bearings inside the engine.
Experiencing abnormal engine noise during rapid acceleration is quite common, with various possible causes. The most frequent issue is combustion knock—poor fuel quality or improper air-fuel ratio can cause a metallic knocking sound when accelerating hard, often due to low octane fuel or aged spark plugs. Another possibility is mechanical wear, such as loose connecting rod bearings or faulty valve lifters, which produce a tapping noise under sudden load. Belt slippage can also create squealing sounds, indicating issues with the tensioner or water pump. Ignoring these problems long-term risks internal engine damage and costly repairs. To identify the issue, listen carefully: Is it a sharp detonation sound? A grinding noise? Preventive measures include regular maintenance, using high-quality fuel, and checking belt tension every six months. If symptoms arise, promptly visit a repair shop for diagnosis—delaying may worsen damage.
