What was found
ENROUTE, PILOT OBSERVED LEFT ENGINE OIL TEMPERATURE APPROACHING THE RED LINE ON THE INDICATOR. ALL OTHER ENGINE INDICATIONS NORMAL. SHUTDOWN LEFT ENGINE AS A PRECAUTION, DECLARED AN EMERGENCY AND DIVERTED, LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED LEFT ENGINE OIL LEVEL, OIL COOLER AND OIL FILTER NO DISCREPANCIES NOTED. PERFORMED A GROUND RUN FOR 20 MINUTES, OIL TEMP WAS INDICATING NORMAL RANGE. LEFT ENGINE OIL INDICATION TEMP BULB WAS REPLACED AS A PRECAUTION. OPS CHECK FLIGHT WAS PERFORMED WITH NO DISCREPANCIES NOTED. OIL TEMPERATURE INDICATION WAS NORMAL ON SUBSEQUENT FLIGHTS.