As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR CONDITIONING SMELLS LIKE DIRTY SOCKS. RAN APU FOR ONE HOUR. VERY WEAK OIL ODOR WHEN BLEED AIR IS FIRST TURNED ON. COMPLIED WITH ENGINE RUN UP AND TURNED ON BLEED AIR, STILL A VERY WEAK OIL ODOR NOTED. REMOVED AND REPLACED APU AND TURBOCOOLER IAW MM 49-10-01 AND 21-52-03. OPS AND LEAK CHECKED GOOD.