What are the causes of engine abnormal noise in Geely New Vision?

[SanMaria]

Most common abnormal noises in the engine depend on the engine's speed state. Below are the relevant introductions about abnormal noises: 1. The noise only exists during idle or low-speed operation. Possible causes include: excessive clearance between the piston and cylinder wall; overly tight piston pin or connecting rod bearing assembly; excessive clearance between the tappet and its guide hole; wear of the camshaft profile; sometimes, a loose starter clutch causing pulley noise (more noticeable during speed changes). 2. The noise becomes chaotic at a certain speed, and short noises are emitted successively during rapid deceleration. Possible causes include: cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive axial clearance of the camshaft or loose bushing. 3. The noise appears during rapid acceleration of the engine and persists during high-speed operation. Possible causes include: loose connecting rod bearings, melted or mismatched bearing shells causing rotation; loose crankshaft bearings or melted bearing shells; broken piston pin; broken crankshaft.