Why is the car's acceleration sound loud?
1 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.