"Clean all connections on your
"Clean all connections on your water temp sensor and your oil pressure sensor. It could be a false alarm from bad connection, or even a failing sensor. Use a guage to measure actual oil pressure while running, both engine cold and hot. An hand held InfaRed temp guage could be used to measure various locations about the engine, as discussed in numerous other threads.
I had a case where oil pressure was good at startup (45 psi) but gradually dropped to zero after engine was at operating temp. A second guage screwed in place of the sensor revealed the sensor was failing and oil pressure was really fine."