As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 100-HOUR INSPECTION, ALUMINUM SHAVINGS WERE FOUND IN THE OIL FILTER. SUBMITTER STATED THIS 5TH TIME THIS SHOP HAS HAD THIS PROBLEM IN THE LAST 18-24 MONTHS). ALUMINUM IS FROM PISTON PIN PLUGS RUBBING AGAINST THE LOWER PART OF THE CYLINDER WHICH, AFTER 400-500 HOURS, DEVELOPED SEVERE PITTING THEN CREATED A WEAR STOP IN THE CYLINDER WALLS. ONE ENGINE LOST COMPRESSION IN ALL 4 CYLINDERS BELOW ACCEPTABLE LIMITS. (X)