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. ACFT GROUNDED. RAN APU FOR 15 MINUTES, FOUND SMALL OIL LEAK AT OIL TANK MAGNETIC DRAIN PLUG FITTING. REMOVED DRAIN PLUG AND REPLACED O-RINGS IAW AMM 49-91-81. RAN APU FOR VERIFICATION NO LEAKS NOTED.