What is the reason for the abnormal noise when shifting gears in the Mercedes-Benz C200L?

[Viola]

Mercedes-Benz C200L has abnormal noise when shifting gears for the following reasons: Abnormal piston condition: Excessive clearance between the piston and cylinder wall; the piston pin is assembled too tightly or the connecting rod bearing is assembled too tightly; excessive clearance between the tappet and its guide hole; wear of the cam profile; sometimes, the starting claw is loose, causing the pulley to make noise (especially noticeable when the speed changes). Abnormal camshaft timing gear: The camshaft timing gear is cracked or its fixing nut is loose; the crankshaft is broken; the piston pin bushing is loose; the camshaft axial clearance is too large or its bushing is loose. Abnormal bearing condition: The connecting rod bearing is loose, the bearing shell is melted or the size does not match and rotates; the crankshaft bearing is loose or the bearing shell is melted; the piston pin is broken; the crankshaft is broken.