As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE STARTED RUNNING ROUGH JUST AFTER TAKEOFF, PILOT RETURNED TO AIRPORT. MAINTENANCE INSPECTED ENGINE AND FOUND ZERO COMPRESSION ON NR 5 CYLINDER AND METAL CONTAMINATION IN OIL FILTER. ENGINE WAS REMOVED AND SENT TO ENGINE SHOP FOR FURTHER INVESTIGATION.