What was found
DURING CLIMB OUT, OIL QUANTITY IN #2 ENGINE DECREASED TO ZERO, DID NOT MOVE FROM ZERO FOR REST OF FLIGHT, ALL OTHER INDICATIONS REMAINED NORMAL. RETORQUED ENGINE OILTANK OIL IN COUPLING NUT IAW AMM 79-11-01, PERFORMED IDLE LEAK CHECK 3A AND PART POWER LEAK CHECK 3B IAW B737 AMM 71-00-00, NO LEAKS NOTED. EMERGENCY DECLARDED. RETORQUED ENGINE OILTANK OIL IN COUPLING NUT IAW B737 AMM 79-11-01, PERFORMED IDLE LEAK CHECK 3A AND PART POWER LEAK CHECK 3B IAW B737 AMM 71-00-00, NO LEAKS NOTED.