As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAH - FLT 4286, THE CREW REPORTED THAT IN FLIGHT THE NR 1 PACK MAKES LOUD GROANING NOISE AND SMELLS LIKE BURNING OIL / PLASTIC. THE AIRCRAFT LANDED AT IAH WITHOUT INCIDENT WHERE MAINTENANCE REMOVED AND REPLACED THE NUMBER ONE ACM, OPERATIONALLY TESTED WITH NO DEFECT NOTED, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.