As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU (EXCEPT GENERATOR): AFTER TAKE STRONG SMELL IN AC MORE LIKE BURNING OIL OR CLEANING FLUID. SHUT DOWN APU SMELL WENT AWAY. AFTER LANDING STARTED APU SMELL RETURNED. REMOVED AND REPLACED COALESCER SOCK WITH NEW. OPS CHECK LEAK CHECK GOOD. DONE IAW MM 21-50-00.