What was found
ON LANDING, AFTER STARTING APU, CABIN FILLED WITH BLUE SMOKE, HAZE AND ODOR. SHUT OFF PACKS. SMOKE DISSAPATED. MAINTENANCE FOUND APU OIL PRESENT IN APU AIR INLET AND SUSPECTED OIL LEAK. WASHED APU ENGINE AND COMPARTMENT, RAM AND NON RAM AIR INTAKES, AND OPERATED APU BLEED AIR AND RAN 2 PACKS IAW AMM 49-90-00. ACCOMPLISHED CABIN ODOR TROUBLESHOOTING AND PACK CLEANED OUT, BURNOUT IAW AMM 21-20-02. AIRCRAFT WAS GROUNDED.