When the engine is operating between approximately 2200 and 2400 RPM the analog oil pressure indicator oscillates +/- 5 psi at high frequency. This is a relatively new oil pressure/temp gauge. The original pressure gauge failed a while back. It would indicate 45 psi after the engine stopped and would only go to zero when tapped.

Is the vibration a problem with the gauge, or is the natural frequency of the needle being forced by a prop vibration? I am currently trying to schedule someone to do a dynamic balance on the prop. There are other indications of prop imbalance (exhaust bolt wear, wear in the air box, wear in the throttle shaft).

Thoughts?
Thanks,
Barry