As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK INFLIGHT T1889/08JUN - DURING CLIMB AIRCRAFT FILLED WITH SMOKE. RETURNED TO JFK AND LANDED WITHOUT INCIDENT. FOUND OIL COOLER REGULATOR VALVE LEAKING. REPLACED OIL COOLER REGULATOR VALVE AND PACKING. REPLACED BOTH PACK COALESCER BAGS. SYSTEM GROUND CHECKED NORMAL OPERATION.