"Kyle Boatright" wrote

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.

That is a lot of time and hours on a sender. I would be surprised if it is
not the sender.

Most senders fail when oil gets past the pressure side, and gets into the
dry side. You really can't usually see the problem, but sometimes, you can
see oil (a small amount) oozing out around where the wires hook on.

If you put voltage onto one lead of the sender, you should see the other
terminal voltage go up and down with RPM. If not, bad sender. You can
check the gauge by inputting differing voltages, from zero to 12 (or 28) and
watch the oil pressure go up and down.

If the sender is fairly inexpensive, replace it. It is due. Your mileage
may vary.
--
Jim in NC