What was found
PILOT REPORTED ELEVATED NR 3 CYLINDER CHT WHILE ALL OTHER PARAMETERS REMAINED NORMAL. PLANE WAS BROUGHT TO US AFTER FAULT COULD NOT BE FOUND BY LOCAL SHOP. WE PERFORMED A RESISTANCE CHECK OF THE PLUGS ON THE SUSPECT CYLINDER AND FOUND 1 TO HAVE INFINITE RESISTANCE VALUE AND OTHER WAS READING OVER WHAT TEMPEST PUBLISHES FOR SERVICE LIMITS. BOTH BAD PLUGS WERE CHECKED ON THE SPARK PLUG TESTER IAW THE SERVICE INSTRUCTIONS PROVIDED BY THEIR MFG WITH PASSING RESULTS AS MFG DOES NOT LIST RESISTANCE VALUE LIMITS IN THEIR GUIDANCE. THE ENTIRE SET OF SPARK PLUGS WERE R & R WITH TEMPEST OF THE SAME PN AND PROBLEM WAS CORRECTED.