As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF FLIGHT, CREW NOTICED FORWARD CARGO SMOKE WARNING FOLLOWED BY FIRST CLASS LAV SMOKE DETECTOR SOUNDING. PILOT AND FIRST OFFICER BOTH SMELLED EXHAUST/OIL. FLIGHT CREW RETURNED AIRCRAFT TO DEPARTURE AIRPORT. NO EVIDENCE OF FIRE FOUND. CARGO SMOKE CONTROL PANEL REPLACED, FIRST CLASS LAV SMOKE DETECTOR AND WATER SEPARATORS REPLACED. ENGINE NR 1 REMOVED AND REPLACED ON THE FOLLOWING DAY SEE LOGS 4345641 AND 4345644.