What was found
(CAN) ENGINE EQUIPPED WITH NEW STEEL ENGINE COPONENTS IN (ECI)CYLINDER ASSY'S P/N AEC631397ST71.2A, 606.4 HR TOTAL TIME. CYLINDER NR 4 WAS FOUND CRACKED IN THE CYLINDER HEAD JUST BELOW TOP SPARK PLUG HOLE. (SDR WAS ISSUED) AT 706.0 HRS CYLINDER 2 AND 6 WERE ALSO FOUND TO BE CRACKED IN THE SAME LOCATION. ALL CYLINDERS WERE CHECKED AGAINST S/N TO COMFIRM THAT THEY WERE NOT AFFECTED BY ECI SB 04-1 (AD 2004-08-10) AND ALL WERE FOUND TO BE NOT APPLICABLE BY THEIR SERIAL NUMBERS. AS A RESULT OF THE DISCOVERY OF THESE CRACKED CYLINDERS AND THAT ALL CYLINDERS WERE INSTALLED NEW AT ENGINE OVERHAUL. ALL 5 ORIGINAL INSTALLATION CYLINDERS WILL BE REPLACED WITH NEW CYLINDER ASSY.