A Line Mechanic reports about an A319 returning to the airport two times with dropping engine oil pressure; rising engine oil and IDG temperatures after they changed the #2 engine. An engine oil overserviced condition was apparently caused by the CFM-56 remaining in storage for almost two years with no requirement to drain the oil prior to placing engine back in service.

Narrative

This is my first day back from my weekend following the event. We began an engine change on #2 motor. The next morning; per the Engine Change Job Card XXX; step one; it says to make sure the engine oil; IDG; and starter oil levels are correct. I serviced the oils to the correct levels on the IDG; starter; and oil tank. The IDG was correct; the starter was correct; and the oil tank took five quarts to be filled up. We ran the engine for 15-20 minutes for an idle leak check. There was no leaks on the engine. When I turned off the motor; I went to check the oil tank levels and the level was correct. I popped off the oil cap and no oil came out. I put the cap back on and closed up the cowls and taxied the A319 to the gate. At no time did the engine oil temp; pressure; or quantity change to an unacceptable level during our engine runs giving us any cause for concern. The aircraft left a few hours later on a ferry flight; and had an inflight engine shutdown ten minutes into the flight due to engine oil temp rising above 135 F. The aircraft returned to the gate with an emergency landing. Upon arrival; the engine had lost oil out of the tail cone; and had come out of the cap when opened. About 2-3 quarts were lost when the cap was opened. Troubleshooting led us to believe it was a Fuel Return Valve (FRV). After changing the FRV; and another ATB (Air Turnback); I realized the oil system was overserviced. After consulting with Engineering and General Electric; we drained all of the oil out of the motor and re-serviced the motor per the AMM. The engine oils and temps were serviced correctly and had a test flight without any further issues. Due to the time the engine had sat in ZZZ before it was sent to ZZZ1 and the time it was in storage; preserved here [in ZZZ1]; I believe oil had settled into the accessory gearbox and transfer gearbox; giving us an incorrect indication to the engine's actual quantity when I serviced it. When I serviced [the oil] to the mark on the sight glass; it was already overserviced at that point. If the Job Card had a step to drain all oil out of the oil tank and gearboxes regardless; I believe it would have prevented this altogether.