What was found
SPARK PLUGS, TEMPEST: UPON REMOVAL, 4 OF THE 12 SPARK PLUGS, FOUND TO HAVE CIRCUMFERENTIAL CRACKS IN STEEL SHELL, LOCATED IN REDUCED ALL HOT CRIMP (SWAGE) SECTION BETWEEN THE MOUNTING GASKET SEAT & WRENCHING HEX. CRACKS ARE JAGGED & IRREGULAR, EXTEND AROUND A MAJORITY OF THE SHELL CIRCUMFERENCE, & ARE VISUALLY DISTINCT FROM THE NORMAL MACHINED STEP AND FACTORY HEATING BAND IN THIS AREA. SHELL MARKINGS ON THE INSERVICE PLUGS: X061/OPDA. (2) FACTORYNEW PLUGS: BASED ON THE ABOVE FINDINGS, REPLACEMENT OF ALL 12 PLUGS WAS ELECTED. DURING PREINSTALLATION INSPECTION, 7 OF THE 12 NEW PLUGS WERE FOUND CRACKED AT THE SAME SHELL LOCATION. THESE PLUGS ARE NEW IN ORIGINAL FACTORY PACKAGING & HAVE NEVER BEEN INSTALLED, TORQUED, OR EXPOSED TO ENGINE OPERATION. CRACKS RANGE FROM PARTIAL CIRCUMFERENCE FISSURES TO NEAR COMPLETE CIRCUMFERENTIAL.