As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PERFORMED ANNUAL INSPECTION ON ENGINE, FOUND BLACK (FRETTING) CORROSION BELOW CENTER 2 (LT AFT) ENGINE MOUNT BOLTS. BOLTS WERE LOOSE IN MOUNT, BUT THE NUTS WERE TIGHT ON BOLTS. PROBLEM IS THAT THE BOLTS ARE A LITTLE TOO LONG AND THE NUTS WERE RUNNING OUT OF THREADS ON THE BOLTS. SOLUTION WAS TO ADD ANOTHER WASHER BELOW THE NUTS, THEN RETORQUE BACK TO SPECS. (K)