As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CLIMB FLIGHT ATTENDANTS REPORTED ODOR IN CABIN. ODOR DISSIPATED AFTER QRH PROCEDURE WAS ACCOMPLISHED AND RETURNED DURING DESCENT AFTER LANDING GEAR EXTENSION. ODOR STRONGEST AT MID AND AFT CABIN. DURING THE TROUBLESHOOTING OF THIS EVENT MAINTENANCE FOUND THE #1 ENGINE EXCHANGER PRECOOLER DAMAGED AND LEAKING. MAINTENANCE REPLACED THE EXCHANGER PRECOOLER AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER AMM 36-11-42.