What was found
DESCENDING THROUGH 6K AFT FA CALLED WITH ODOR DESRIBED AS BURNT POPCORN. AT 3K PURSER CALLED AS SHE COULD NOW SMELL ODOR, SHE SAID WAS DIRTY SOCK. PILOTS NEVER SMELLED ANY ODOR. ODOR SEEMED TO BE TEMPORARY IN NATURE. FOUND OIL IN #2 ENG. REPLACED #2 ENG FAN SHAFT COVER O-RING PER A321 AMM 72-15. PERFORMED HIGH POWER ENG RUN ON BOTH ENGINES PER A321 AMM 71-00. COMPLETED LVL A DECONTAMINATION W/C 2100-2007 OPS CHK GOOD NO SMOKE OR FUMES SMELLED ON A/C. (LP 8547426 - AIRCRAFT WAS GROUNDED)