As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND PROPELLER GOVERNOR OIL LINE FITTING LEAKING OIL. CAUSED WHITE SMOKE IN FLIGHT DUE TO OIL LEAKING ON EXHAUST. POSSIBLE CAUSE, FITTING NOT PROPERLY TORQUED AT PROPER GOVERNOR OVERHAUL. RECOMMEND CHECKING TORQUE OF FITTING ON INSTALLATION OF PART.