As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE WAS DISASSEMBLED AND INSPECTED FOR PROP STRIKE INSPECTION. DURING TEST CELL OPERATION THE TECHNICIAN NOTICED AN OIL LEAK AT THE NR4 CYLINDER. FURTHER INSPECTION REVEALED THAT THE PUSH ROD TUBE RETAINER BROKE INSIDE THE ROCKER COVER CAUSING THE TUBE AND SEAL TO FALL OUT OF POSITION.