The gen-5 engine-and-transmission year — walk if the 3.5L shows coolant in the oil or the transmission slips.

The 2017's other expensive pattern is the automatic: complaints describe intense vibration at stops, hesitation pulling away, harsh downshifts, and torque-converter failures — several owners on their second or third transmission. One reports 'three transmissions replaced from 2023 to 2026' because 'Ford no longer makes 2017 Explorer transmissions,' so replacements are salvage or remanufactured and quality varies. Ford's Customer Support Program 20N07/20B27 extends transmission coverage and adds a torque-converter reflash (plus a 12-month torque-converter warranty from the reflash) on 2.3L cars; V6 owners have less recourse. Sustained slip or shudder that a dealer reflash can't cure is a walk-away sign.

As on the 2016, all-wheel-drive 2017s leak oil from the Power Transfer Unit's pinion seal — the gearbox that drives the rear axle, sitting under the exhaust. The factory fluid is sealed for life, so once it weeps it overheats and the unit fails; a shop mechanic says he has 'replaced over 20.' Prevention is a fluid change every 15,000-20,000 miles. Check underneath for oil around the PTU and ask about fluid service history.

On 3.5L GTDI (twin-turbo) cars, improperly brazed turbocharger oil-supply tubes can leak oil onto hot engine components — a fire risk — under recall 16V-925. One 2017 owner in the file reports white exhaust smoke from oil entering the exhaust after a turbo failure, which then killed the oxygen sensors. The recall repair (inspect and replace the oil-supply tubes) is free. Verify by VIN that 16V-925 was completed on any twin-turbo car.

The 2017 shares the gen-5 recall and program stack: the carbon-monoxide/exhaust-odor Customer Support Program 19N05 (2011-2017), the rear toe-link fracture recalls (19V-435, salt-belt expansions 20V-675/21V-537, and a 2017-2019 expansion 26V-101), and the A-pillar (24V-031) and B-pillar (25V-347) trim-detachment recalls that dominate recent complaints with parts-delay reports. All are free — the issue is confirming they were actually done and parts were available.