As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: NOTICEABLY OIL SMELL DURING DECENT AND LANDING WITH APU OFF, AFTER LANDING WHEN BOTH ENGINES WERE SHUT DOWN AND THE APU BLEED WAS TURNED ON, THE OIL SMELL BECAME MORE STRONGER. AIR DUCT CAN HAVE A POSSIBLE OIL CONTAMINATION. THE OIL SMELL CAN BE SMELL AT THE ENTIRE CABIN AT THE GATE. MAINTENANCE FOUND THE APU OIL COOLING FAN LEAKING OIL AND REPLACED IT PER AMM 49-52-51.