As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT 13,000, THE CREW BEGAN GETTING A LEFT HAND ENGINE SURGE. THE CREW FOLLOWED THE QUICK REFERENCE HANDBOOK AND CONTACTED MAINTENANCE CONTROL. THE CREW THEN DIVERTED TO PHL. NO EMERGENCY WAS DECLARED AND THE FLIGHT LANDED SAFELY AT PHL. TWO MECHANICS FROM PIT WERE SENT TO INSPECT THE AIRCRAFT. MAINTENANCE THEN REPLACED THE HYDROMECHANICAL UNIT IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 73-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.