What was found
DEPARTED, ENROUTE, THE AIRCRAFT ENGINE OIL PRESSURE LIGHT STARTED INTERMITTENTLY TO COME ON AND OFF THEN STAYED ON CONTINOUS WITH A GONG SOUND FOLLOWING. REFERRED TO AS350B3 EMERGENCY GUIDE, REDUCED POWER, AIRSPEED, AND AT 2148 ADVISED OPERATIONS OF THE SITUATION AND DIVERTED TO AIRPORT. MONITORED THE OIL PRESSURE AND ENGINE TEMPERATURE WHILE DESCENDING, SLOWING DOWN THE AIRCRAFT AND MAINTAINING A SAFE ALTITUDE IN THE EVENT OF AN ENGINE FAILURE. THE OIL PRESSURE WAS SLOWLY DROPPING BUT THE ENGINE TEMPERATURE WAS WITHIN NORMAL RANGE. APPROXIMATELY 2 MINUTES FROM AIRPORT, THE OIL PRESSURE DROPPED TO .5 , LANDED.