The 2019-2021 Nautilus with the 8-speed automatic can have harsh 1-2/2-3 shifts, delayed downshifts, clunking while decelerating, and occasional transmission fault or reduced-power messages. Stop-and-go test drives may reveal jerkiness, hesitation, and gear hunting. A transmission-control-module reprogram and fluid service often resolves it, but ignoring the symptoms can lead to valve-body damage or full transmission replacement.

The 2019-2020 Nautilus with the 2.7L twin-turbo EcoBoost can suffer excessive oil consumption, low-oil warnings, oil leaks, and coolant loss. Inspect the oil level when cold, look for fresh fluid stains, and watch for blue/white exhaust smoke or a gasoline/coolant smell in the oil. Continuing to drive with very low oil risks internal engine damage, and repairs like intake-valve-seal or oil-consumption work are costly.

The 2019-2021 Nautilus (and similar platform through 2023) can lose A/C cooling from an evaporator-core refrigerant leak, often first noticed as warm air at idle, a sweet/solvent interior odor, or a visible under-dash leak. Run the A/C on Max for several minutes during a test drive and check vent temperature and compressor cycling. Once the core fails, the dashboard must be removed for replacement.

The 2019-2023 pre-redesign Nautilus can have SYNC 3/infotainment freezing, black screens, audio cutouts, Bluetooth failure, and backup-camera blackouts that persist until restart. Test the touchscreen and cycle through FM, Bluetooth, and navigation, then shift into Reverse several times to confirm the camera displays. The APIM/SYNC module may need reprogramming or replacement if the failures recur.