As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE TWO REPORTED ENGINES EXHIBITED FUEL STAINS ADJACENT TO THE ENGINE FUEL INJ ECTORS ON 9 OF A POSSIBLE 12 CYLINDERS. FURTHER EXAMINATION REVEALED CYLINDER HEAD CRACKS UNDER CYLINDER FINS (AT THE INTAKE PORTS) AND THROUGH THE SPARK PLUG BOSSES ON EACH OF THE CYLINDERS. SUBMITTER STATED IF ALLOWED TO GO UNCHECKED, THE CRACKS COULD PROGRESS TO A POINT WHERE THE CYLINDER TO HEAD INTEGRITY WOULD BE LOST AND CYLINDER PERFORMANCE JEOPARDIZED.