As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ON DESCENT APPROX FL 220, ENGINES AT IDLE, MUST ACRID ODOR IN CABIN, MOST NOTICEABLE IN COCKPIT. ODOR CLEARED THEN BECAME NOTICEABLE AGAIN AT FL100-NOTHING VISIBLE. MAINTENANCE FOUND THE #1 ENGINE STARTER DRIVE SEAL ASSEMBLY LEAKING OIL AND REPLACED IT PER AMM 72-60-22. A SATISFACTORY LEAK AND OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ODORS NOTED.