What was found
AT ALTITUDE, RECEIVED RT ENGINE OIL WARNING MESSAGE. (FL30.0 APPROX 80 PERCENT N1) RETARDED THROTTLE TO 76 PERCENT N1 WARNING EXTINGUISHED, PRESSURE READ 33 PSI. AFTER 5 MIN WARNING RETURNED. AT THROTTLE IDLE PRESSURE INDICATED 30 PSI. INDICATION FLUXUATED 5 PERCENT AT ALLN1 SPEEDS. ALL OTHER ENGINE INDICATIONS NORMAL. INSPECTED AND FOUND SIGNIFICANT AMOUNT OF OIL LEAKING FROM ENG. FOURN RT ENG SCAVENGE PUMP OIL FILTER HSG O-RING MISSING, INSTALLED O-RING M83248-1-136. SERVICED 7 QTS OF OIL. VERIFIED OIL REPLENISHMENT, SYS OPS NORMAL.