What was found
PILOT DEPARTED THE AIRPORT FOR A TOUR FLIGHT AND AN ENGINE CHIP WARNING LIGHT CAME ON. THE PILOT RETURNED TO THE AIRPORT. MX PULLED THE UPPER AND LOWER CHIP PLUGS AND FOUND A SMALL AMOUNT OF MATERIAL ON THE UPPER PLUG .79MM OR LESS IN SIZE. AFTER A 30 MINUTE PENALTY RUN THE SAME AMOUNT OF MATERIAL WAS FOUND ON THE UPPER PLUG. THE ENGINE OILS WERE DRAINED, FLUSHED, SEVICED AND THE FILTERS WERE CLEANED. A SECOND 30 MINUTE RUN WAS PERFORMED. MATERIAL WAS AGAIN FOUND ON THE UPPER PLUG. THE ENGINE WAS REMOVED FROM THE ACFT FOR INSP.