As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: STRONG FUMES/ODOR OF OIL IN CABIN AND COCKPIT ON CLIMB OUT THEN DISSIPATED WITHOUT FLIGHT OR CABIN CREW ACTION. FUMES/ODOR RETURNED ON DESCENT, DISSIPATED WITHOUT FLIGHT OR CABIN CREW ACTION. EMERGENCY WAS NOT DECLARED. REPLACED SIGHT GLASS (AALA202105119013) AND O-RING PER CMM 49-25-69. RE SERVICED OIL. LEAK CHECK GOOD.