As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU OIL MONITORING DATA SHOWS OIL CONSUMPTION TO BE TRENDING HIGHER THAN EXPECTED. GROUNDED - YES. ACCOMPLISHED GVI OF TURBINE DUCT FOR EXCESSIVE OIL WITH VIDEO BORESCOPE THROUGH EGT PORT 1, NO OIL OR OIL STAINING NOTICED, IAW B737-800 FIM 49-95 TASK 801. WHILE ACCOMPLISHING FIM TASK 49-95 TASK 801 DETERMINED OIL CONSUMPTION DUE TO LEAK FROM FCU. REMOVED AND REPLACED FCU REF B737-800 AMM 49-31-11-400-801. OPS CHECK GOOD. NO OTHER LEAKS NOTED FROM FCU OR APU.