As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUME EVENT AFTER ENTERING MOISTURE WE HAND NUMMEROUS EVENT. 1ST START AROUND FL 210 ANDIPERIODICALLY WOULD CYCLE ALL THE WAY DOWN TO 4000FT. -R/R RECIRCULATING FILTER IAW AMM 21-21-41. PERFORMED PACL BURN OUT WITH ENGINES IAW AMM 21-00-00-615-004. NO ODOR NOTED AT THIS TIME. PERFORMED GVI OF APU COMPARTMENT IAW TI 2100-2002-NED WO# 324873. NO EVIDENCE OF OIL CONTAMINATION/ LAEKS. A/C OK FOR SVC.