What causes abnormal noise when accelerating the car?
1 Answers
Abnormal noise when accelerating the car is caused by: 1. Excessive clearance between piston and cylinder wall, overly tight piston pin assembly or connecting rod bearing assembly, excessive clearance between tappet and its guide hole, worn cam profile of valve train, sometimes loose components causing pulley noise; 2. Cracked camshaft timing gear or loose fixing nut, broken crankshaft, loose piston pin bushing, excessive axial clearance of camshaft or loose bushing; 3. The abnormal noise occurs during rapid acceleration of the engine and persists during high-speed operation. The causes include: loose connecting rod bearings, melted or mismatched bearing shells rotating, loose crankshaft bearings or melted bearing shells, broken piston pin, or broken crankshaft.