As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) HIGHER THAN EXPECTED CYLINDER HEAD TEMPERATURE (CHT), FOLLOWED BY DECREASING RPM AND A KNOCKING NOISE THAT PROGRESSIVELY GOT LOUDER. ON INSPECTION IT WAS FOUND THAT THE #3 CYLINDER WAS CRACKED STARTING FROM THE BOTTOM SPARK PLUG HOLE HEADING TOWARD AND PASS THE EXHAUST VALVE AROUND THE CYLINDER ABOUT 180 DEGREES. (TC# 20190723008)