What was found
DURING CLIMB, HAD A MASTER WARNING ANNUNCIATOR & LT OIL PRESS ILLUMINATE. NOTED A LT ENGINE OIL PRESSURE READING 45 PSI. RT ENGINE INDICATED 75 PSI. DURING NEXT 90 SECS, LT ENGINE OIL PRESSURE VARIED BETWEEN 45 & 55 PSI. RT ENGINE REMAINED STEADY AT 75-80 PSI. LT ENGINE STABILIZED. AFTER LANDING, NOTICED LT ENGINE OIL LEVEL SIGHT GAUGE INDICATING NO OIL. 4 DAYS PREVIOUS WITH NO OIL LEVEL VARIANCE NOTED. R & R LT ENGINE WITH A REPLACED ENGINE & COMPLIED WITH ALL OPS AND LEAK CHECKS IAW MM 79-00-04.