As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WITHIN LIMITS BUT UNECESSARY THIS SEEMS RELATED TO OIL TYPE MOST OF THE LEAKS START WHEN THE OIL IS CHANGED FROM SUMMER TO WINTER OILS. OUR BEST RESULTS OF NO LEAK IS WITH MOBIL 254 MIL-L-23699 WHICH IS ONLY APPROVED FOR SUMMER OPERATIONS. WHEN WE CHANGE TO THE WINTER OIL MOST TIMES A LEAK IS GENERATED. THE 254 IS ONLY APPROVED FOR -20 DEGREES CELCIUS.