What was found
AFTER LANDING A BURNING SMELL WAS NOTICED IN THE COCKPIT DURING TAXI. SEEMED TO BE COMING FROM MAIN GASPERS UP FRONT. UPON SHUTDOWN WE INSPECTED THE TIRES, THE NOSEBAY AVIONICS, THE AFT EQUIPMENT BAY FOR ANY SIGN OR SMELL. COULD NOT LOCATE. TURNED THE COCKPIT TEMPERATURE CONTROL WARMER THE ODOR DISSIPATED. TURNING IT COLD MADE THE ODOR RETURN. PERFORMED AIR CONDITIONING SYS OPS CHK, RAN EACH PACK INDEPENDANT OF EACH OTHER & NOTICED SLIGHT BURNING ODOR LIKE HOT METAL, NOT OIL OR FLUID RELATED ONLY COMING FROM LEFT PACK, ODOR DISSAPEARS WITH RT PACK ON, LT PACK OFF, ALSO OBSERVED ODOR WILL DISSIPATE IF TEMP IS DRIVEN TO FULL HOT WITH LESS DEMAND ON THE ACM, SUSPECT LT PACK ACM CAUSING ODOR, REMOVED HOT SIDE & COLD SIDE PLUMBING FROM LT ACM, DID NOT OBSERVE ANY SIGNS OF BURNT OR SCORCHED METAL, ACM SPINS FREELY WITH NO SIGNS OF BLADE RUBBING, REMOVED LT WATER SEPERATOR AND INSPECTED, NO DEFECTS NOTED, WATER SOCK SMELLED CLEAN. RESTORED ALL CONNECTIONS AND RAN SYS AGAIN WITH SAME RESULTS. CONTACTED AMCC WITH RESULTS, AT THIS TIME AMCC HAS ELECTED TO DEFFER THE LT PACK IAW MEL 21-51-2-1, CAT C, INOP PLACARD WITH PLACED.