B737-700
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 439
Aircraft Equipment Problem Less Severe
Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Inflight Shutdown; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Aircraft
Approximately 120 to 160 miles east of ZZZ; the number 2 engine oil quantity slowly dropped and did not indicate secondary malfunctions. We had the Jumpseat Pilot check to see if he could see any signs of leaking; which he could not. We began to look at contingency fields; informed the Company of our situation; and formed a plan of action 'just in case'. About five minutes after the oil quantity reached zero; oil pressure began to slowly drop. When the oil pressure continued its downward trend; the Captain called for a precautionary divert to ZZZ. Approximately 25 miles from the field; the oil pressure intermittently flashed in the yellow and red so we shut the motor down and landed uneventfully at flaps 15.
Approximately 100 miles east of ZZZ; the #2 engine oil quantity was slowly dropping. We looked through QRH Checklists and informed the Company we were prepared to divert to ZZZ if it became necessary; although; the pressure and temperature remained normal. We had a Jumpseat Pilot in the back look for indications of a leak on the wing and he noticed nothing. About five minutes after the quantity reached zero; the oil pressure began fluctuating; so I made the decision to [notify ATC] and divert to ZZZ. We brought the Jumpseater up to assist us and be an extra set of eyes and hands. On outside downwind the low oil pressure yellow and red lights began to flash intermittently; so we ran the QRH and shut down the engine. The flaps 15 landing was overweight by 2000 pounds; but otherwise was uneventful.
B737 flight crew reported #2 engine oil quantity decreased to zero followed by loss of oil pressure.