As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED, WHEN NR 2 PACK IS RUNNING THERE IS CLUNKING NOISE AND BAD ODOR. WHEN NR 2 PACK IS TURNED OFF, NOISE AND ODOR GOES AWAY. PERFORMED FIM TASK 21-51-00-810-824-A BLOCK 1 THRU 7 AND R & R NR 2 PACK VALVE IAW AMM 21-51-01 AND R & R OVER TEMPERATURE SWITCH IAW AMM 21-51-08. REMOVED AND REPLACED AIR CYCLE MACHINE IAW AMM 21-51-03-000-801-A AND 21-51-03-400-801-A. OPS CHECKED GOOD. ACFT RETURNED TO SERVICE.