As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CLEANING THE ROCKER ARM, SOLVENT FLOW THROUGH THE OIL PASSAGE WAS FOUND TO BE RESTRICTED. INSPECTION REVEALED A BROKEN DRILL BIT TIP TO BE THE OBSTRUCTION IN THE OIL PASSAGEWAY. WHEN THE DRILL BIT TIP WAS REMOVED, NORMAL FLUID FLOW WAS OBSERVED.