X5 vs Nautilus

The 48V battery in 2023-2024 X5 xDrive40i models can short-circuit internally, causing a 'Drivetrain Malfunction' warning and potential sudden power loss. Symptoms include limp mode at low speeds and, in extreme cases, smoke from the battery. This can lead to a dangerous loss of propulsion while driving.

The rear air springs on 2019-2022 X5 models (especially 2019-2020) can leak, causing the vehicle to sag and the compressor to overwork and fail. Symptoms include visible sagging overnight, a continuously running compressor, and a 'Self-Leveling Suspension Inactive' error. If ignored, it can lead to a rough ride and potential strut tower damage.

The plastic oil filter housing and coolant channels on B58 engines in 2019-2023 X5 models can crack, leading to coolant leaks. Symptoms include a sweet coolant odor, visible residue under the vehicle, and low coolant warnings. If not repaired, overheating can warp the cylinder head, resulting in costly damage.

The transfer case actuator motor in 2019-2021 all xDrive models can fail, causing the xDrive system to disengage and a 'Drivetrain Malfunction' warning. Symptoms include shuddering or clunking during low-speed turns and loss of all-wheel drive. The consequence is a potential complete driveline lock-up if the actuator seizes.

The high-voltage battery junction box or charging relay in 2020-2023 X5 xDrive45e and 2024 xDrive50e models can fail, preventing AC charging and triggering a 'High-Voltage System Error'. Symptoms include intermittent charging failures and reduced EV range. Severe cases can cause melted wiring or arcing in the junction box.

The M-Sport brakes on 2019-2023 X5 models are prone to severe squealing on light braking and premature rotor corrosion, even on new pads. Symptoms include a high-pitched metallic squeal at low speeds and possible pedal pulsation. This is a recognized defect covered by a TSB, not normal wear.

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.