As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING INSPECTION FUEL STAINS WERE FOUND AT THE COOLING FIN AREA ON ONE OF THE CYLINDERS. THE CYLINDER WAS REMOVED. FURTHER INVESTIGATION REVEALED A CRACK STARTING ABOVE THE VALVE SEAT UP AND TOWARD THE INTAKE PORT. THE CYLINDER WAS REPLACED.