As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: WET SOCK SMELL IN CABIN. MAINTENANCE FOUND A LEAK BETWEEN THE FUEL CONTROL UNIT AND OIL LUBE UNIT DUE TO A MISSING O-RING, INSTALLED O-RING AND ACCOMPLISHED A SATISFACTORY LEAK / OPERATIONAL CHECK PER AMM 49-32-11.