Cylinder Misfiring

0.5 X

radial, tangential

5 mils

narrow band

No diagnostics can be done until all misfiring is corrected

Imbalance, Misalignment Torque Reaction,

Weak Foundation

1X

radial, tangential

5 mils

narrow band

1X and No. of firing strokes per revolution are caused by torque reaction, which in turn can cause misalignment

Harmonic Balancer

2X

radial, tangential

4 mils

narrow band

Correct by rotating the balancer

Cylinder Combustion Forces

1.5X, 2.5X, etc

radial, tangential

4.3 mils

narrow band

Normal operating levels