What was found
DURING THE ENGINE OVERHAUL, UNDER THE DISASSEMBLY PROCESS, WE FOUND A MOUNTED EXTERNAL SPIN-ON OIL FILTER. HOWEVER, THE ENGINE STILL RETAINED ITS ORIGINAL INTERNAL MESH OIL FILTER. THE ORIGINAL FILTER CONTAINED A SIGNIFICANT AMOUNT OF OIL SLUDGE, DEPOSITS, AND METAL PARTICLES, WHILE THE SPIN-ON FILTER SHOWED NO CONTAMINATION. THE CONCLUSION IS THAT THE MODIFICATION PERFORMED ON THIS ENGINE WAS INCORRECT. WHEN AN OIL FILTER ADAPTER IS INSTALLED, THE ORIGINAL MESH FILTER MUST BE REMOVED SO THAT ONLY THE SPIN-ON FILTER IS IN USE. UNDER THESE CONDITIONS, MAINTENANCE PERSONNEL WOULD TYPICALLY INSPECT ONLY THE SPIN-ON FILTER AND NOT THE ORIGINAL INTERNAL FILTER. THIS CAN LEAD TO THE ORIGINAL FILTER BECOMING CLOGGED, CAUSING ENGINE OIL STARVATION AND RESULTING IN SEVERE ENGINE DAMAGE AS EVIDENCED BY THIS ENGINE AND THE AMOUNT OF DEBRIS FOUND IN THE ORIGINAL FILTER.