As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE, VISUALLY OBSERVED A SMALL AMOUNT OF SMOKE IN THE COCKPIT & THEN THE LT OIL PRESS CB POPPED. AFTER THE CB POPPED THE SMOKE DISSIPATED. RETURNED & LANDED WITHOUT INCIDENT. TROUBLE SHOT THE LT OIL PRESS SYS & FOUND THE INDICATOR HAD SHORTED INTERNALLY. THE LT OIL PRESS INDICATOR & ELEC CONNECTOR WERE REPLACED. THE LT OIL PRESS INDICATOR FUNCTIONED NORMALLY DURING ENG GND RUN.