As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE GEARBOX WAS O/H 7.6 HRS IN SERVICE AND THE PILOT REPORTED AN ENGINE CHIP LIGHT. UPON FURTHER INVESTIGATION OF THE CHIP PLUG, IT APPEARS TO BE A DRILL BIT THAT WAS LEFT IN THE GEARBOX DURING THE O/H PROCESS. IN THE PROCESS OF CHANGING THE ENGINE GEARBOX OUT.