What was found
AFTER STARTING APU WHEN PUTTING APU BLEED AIR ON GOT SMOKE IN THE CABIN. IT WAS A OILY SMELL THAT BURNED EYES AND COULD TASTE. YOU COULD VISIBLY SEE THE SMOKE IN CABIN. FOUND APU OIL OVERSERVICED ABOVE FULL UNE (07 22 SL}. ADJUSTED OIL QTY LEVEL TO IN BETWEEN THE MININUM AND MAXIMUM UNES IAW AMM 12-20-20. PERFORMED COMPRESSOR INLET BORESCOPE INSPECTION IAW TC-C68-49-1001, REVISION 2, WITH NO EVIDENCE OF OIL LEAKAGE OR COKING. VISUALLY INSPCTED APU BLEED AIR DUCT & FOUND IT DRY. VISUALLY INSPECTED APU EXHAUST & FOUND IT DRY. PERFORMED ENVIRONMENTAL CONTROL SYSTEM BLEED & TRIM AIR DUCT BURN PROCEDURE IAW TC-68A-21-181006MR3 FROM THE ENGINES AND APU WITH SATISFACTORY RESULTS.