Engine Vibration

"Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point."

Causes: 

1.       Foundation condition

The foundation bolts on driving end and free end are the most vulnerable. Schedule checking and tightening sequence with specified load required. Also check for cracks on the foundation and the leveling screw and shims condition. 

2.       Crankshaft alignment

Crankshaft alignment is very much important for engine stability. Crankshaft deflection is indicate the alignment between the crankshaft bearings and the bearing of the driving shaft. Following are the possible causes –uneven wear of crankshaft bearings, change in the position of driven shaft or change in the engine seating on the foundation. 

 Read about crankshaft deflection measurement  

3.       Vibration damper

The function of vibration damper is to absorb torsional vibration. Sleeve spring pack used to absorb vibration. If the spring pack broken of wear down then vibration occurs.

4.       Looses or broken parts

This is a common cause of engine vibration. To prevent vibration due to loosen or broken parts schedule nut-bolt tighten checking necessary. Specially check the Turbocharger foundation nut-bolts. 

5.       Exhaust gas back pressure

If exhaust manifold or boiler (in case of EGB) clogged with carbon deposit or some broken part then due to back pressure engine vibration can occurs.