What Causes Continuous Vibration and Abnormal Noise in the Rear of a Honda Accord?

[AshlynLee]

Continuous vibration and abnormal noise in the rear of an Accord can be categorized into the following scenarios: 1. The noise occurs only during idling 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 on the camshaft lobe profile; sometimes, a loose starter clutch causing pulley noise (especially noticeable during speed changes). 2. The noise becomes irregular at a certain RPM, with brief sounds occurring during rapid deceleration. Possible causes include: cracked camshaft timing gear or loose fixing nut; broken crankshaft; loose piston pin bushing; excessive camshaft axial clearance or loose bushing. 3. The noise appears during rapid engine acceleration 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.