A B757-200 OIL QUANTITY SLOWLY DECREASED TO ZERO WITH NORMAL OIL PRESSURE. SLOWLY OIL PRESSURE DROPPED; THE ENG WAS SHUT DOWN; AND AN EMER DECLARED.

Narrative

BEFORE DEPARTING ZZZ WE NOTICED THE OIL QUANTITY FOR THE L ENG WAS AT 19 QUARTS DURING PREFLT PREPARATION. AFTER TKOF AND REACHING CRUISE ALT WE NOTICED THE L ENG OIL QUANTITY HAD DROPPED TO AROUND 6 QUARTS. WE MONITORED THE OIL PRESSURE AND OIL TEMP AND THEY WERE IN THE NORMAL RANGE. A LITTLE LATER IN THE FLT JUST W OF DENVER WE NOTICED THAT THE OIL QUANTITY FOR THE L ENG HAD DROPPED FURTHER DOWN TO 1 QUART. THE OIL TEMP REMAINED IN THEIR NORMAL RANGES. THE OIL QUANTITY THEN DROPPED TO 0 QUARTS AND WE THEN CONTACTED DISPATCH AND MAINT AND DISCUSSED THE SITUATION. MAINT SAID THAT AS LONG AS THE OIL PRESSURE AND OIL TEMP WERE IN THE NORMAL RANGES THEN IT WAS OK TO PROCEED ON TO OUR DEST WITH 0 QUARTS OF OIL IN THE L ENG. HE SAID TO MONITOR OIL PRESSURE AND OIL TEMP AND LET THEM KNOW OF ANY CHANGES. DURING DSCNT ON THE ARR IN ZZZ1 AT ABOUT 24000 FT THE L ENG OIL PRESSURE LIGHT STARTED TO FLICKER. OIL PRESSURE WAS DECREASING BUT STILL IN THE NORMAL RANGE. EVENTUALLY OIL PRESSURE WENT BELOW 80 PSI TO ABOUT 73 PSI AND THE L ENG OIL LIGHT CAME ON STEADY AND WE GOT THE L ENG OIL EICAS MESSAGE. WE THEN WENT TO THE ENG OIL PRESSURE IRREGULAR CHKLIST WHICH LEAD US TO THE ENG FAILURE/SHUTDOWN INFLT CHKLIST. WE PERFORMED AN ENG SHUTDOWN AT ABOUT 11000 FT WE CONTINUED TO ZZZ1 AND MADE A SINGLE ENG LNDG ON RWY 27L. WE HAD THE FIRE AND RESCUE TRUCKS LOOK AT THE L ENG BEFORE TAXIING TO THE GATE ON THE REMAINING MOTOR.