As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4348, CREW REPORTED THAT ATOMIZED TURBINE OIL FUMES WERE INTRODUCED INTO THE CABIN CONDITIONED AIR WHEN USING ENG 1 BLEED AS SUPPLY SOURCE. WHEN USING BLEED 2 OR APU TO SUPPLY A/C PACKS CONDITIONED AIR IS GOOD. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED NR1 ENGINE IAW WORK CARD 71-00-00. AIRCRAFT RETURNED TO SERVICE.