As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING APPROACH, STARTED SMELLING A VERY BAD SMELL THAT RESEMBLED THE SMELL OF HOT OIL OR HOT METAL. FLIGHT ATTENDANTS DIDN'T SMELL IT IN CABIN. MAINTENANCE FOUND THE FORWARD CHILLER OVER HEATING AND REPLACED IT PER AMM 25-34-00. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.