As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)PILOT NOTICED OIL LEAKING FROM ENGINE DURING WALKAROUND. INVESTIGATION FOUND THE OIL WAS COMING FROM THE THREADS OF THE OIL COOLER FITTINGS. THE SEALANT AROUND THE THREADS WAS FOUND TO BE MISSING. NEWSEALANT WAS APPLIED AND THE AIRCRAFT RETURNED TO SERVICE.