As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOR FLIGHT 3281 DURING PREFLIGHT OF AIRCRAFT A VERY STRONG ODOR OF METAL OVERHEATING IN THE NR 1 (LEFT) HYDRAULIC COMPARTMENT. THE ODOR BECAME MUCH WORSE WHEN SELECT HYDRAULIC PUMP WAS ON. THE AIRCRAFT WAS REMOVED FROM SERVICE. PERFORMED OPERATIONAL CHECK OF NR 1 & NR 2 HYDRAULIC PUMPS. NO DEFECTS NOTED AT THIS TIME. REF EMB 140 AMM 29-14-00. NO PARTS REMOVED OR REPLACED. THE AIRCRAFT WAS RETURNED TO SERVICE.