As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WITH THE ENGINE COWLING REMOVED TO REPLACE UNSERVICEABLE LANDING LIGHT, OIL WAS NOTED AROUND THE NR 3 CYLINDER. INVESTIGATION SHOWED SHROUD WAS BROKEN APPROXIMATELY MIDWAY ALONG THE TUBE. AS THE CRACK WAS A RATHER SHARP BREAK THE PROBLEM WAS NOT FOUND UNTIL THE TUBE WAS MOVED (TWISTED) BY HAND.