"Jim Carriere" wrote in message
.. .
Kyle Boatright wrote:

I was out flying this evening (Beautiful evening in North Georgia. We
don't get better flying weather than today...) and noticed that my oil
pressure was "stuck" at 100 PSI. I reduced throttle and RPM, no change,
I increased throttle and RPM, again no change. I tapped the face of the
gauge. No change.

Eventually, I shut down the radios and transponder and turned off the
master switch. The OP gauge fell to zero. Back on with the master and
it's 100 PSI again. By the time I returned to my home field, the pressure
gauge seemed to be acting normal again, so I presume it is going to be an
intermittant problem - the absolute worst kind to diagnose.

Anyway, the gauge and sender are both Rochester brand. Probably 6 years
old (4.5 years flying)with 350 or so tach hours on 'em.

How do I diagnose the problem when it recurrs?

This is a gauge with a remote sender mounted on the engine, right? I ask
that because what you are describing sounds like a wetline gauge with some
air in the line and cold oil.


This is an electronic gauge with a sender mounted on the engine accessory
case.

Maybe the sender is dying. Can you see if the voltage in the electrical
line between the gauge and sender varies with oil pressure? Then you
could eliminate one part or the other.

You could, but that would mean working awfully close to a flailing prop.
I'm not up for that. ;-)

KB