What was found
AIRCRAFT WAS GROUNDED: DURING CRUISE AT FL 360 WE WERE ALERTED TO A LEFT ENGINE OIL QUANTITY OF 4 QTS. OIL PRESSURE AND TEMP WERE INDICATING NORMAL. CONSULTED THE QRH AND THE PROCEDURE SAID TO CONTINUE FLIGHT. AS WE PROGRESSED, THE QUANTITY DROPPED FURTHER TO 1 QT STILL WITH NORMAL TEMP & PRESSURE VALUE INDICATIONS . TO PREVENT POSSIBLE SHUTDOWN AND DAMAGE TO ENGINE, THE DECISION WAS MADE TO DIVERT TO KIN. EMERGENCY DECLARED, LANDED WITHOUT INCIDENT. MAINTENANCE FOUND OIL CAP O-RING DEFORMING AND REPLACED OIL CAP O-RING IAW AMM 79-11-03.