The Mercury Mountaineer, a midsize SUV, can be considered the luxury version of the Ford Explorer. It shares many of the Explorer's main features, as well as being manufactured by a Ford marque that specializes in manufacturing entry-level luxury automobiles. The Mercury Mountaineer is a considerably more expensive SUV than the Explorer, and it is currently in its third generation.
For first-generation Mercury Mountaineers (1997 to 2001), failure of some parts--the mass air flow sensor, differential pressure feedback EGR sensor, intake manifold gasket and front timing chain tensioner--are covered under a recall up to 72,000 miles. Some vehicles may lose operation of the four-wheel drive system, in which case repair costs would vary since the failures are not specific. The 1997 and 1998 vehicles in particular have heating and air conditioning problems due to failure of the heater case and blend door.
First-generation Mountaineers also tend to have transmission and suspension issues. In some vehicles, the gearbox can flare when shifting from second to third gear. This can be fixed by correcting the shift solenoid malfunction. The sway bar links can also bend or break due to rigid original bushings.
Other problems with first-generation Mercury Mountaineers include electrical noise from the audio system at the AM frequency (replace the electric fuel pump), faulty oxygen sensors, heater core leaks (solved with installment of restrictor in heater inlet hose), and noise during hard acceleration (repair kit for timing chain on 4.0-liter V6 engines).
Engine noise is a common affliction in second-generation Mercury Mountaineers (2002 to 2005). It can be resolved by either introducing a redesigned primary chain tensioner or replacement of the transfer case drive chain. Other problems include faulty clutch, which can be resolved by revised clutch packs and reformulated gear lube; and oil leaks from the right side axle, which requires complete axle assembly replacement.
Among the model years of the second-generation Mercury Mountaineers, the 2002 entry has the most problems. Like the vehicles of the first generation, the four-wheel drive system of the 2002 model year can fail to operate, and it is especially problematic to estimate repair cost since its failure is not specific to any one part. Some 2002 Mountaineers may also have premature transmission failure, a problem that is identical to that of the aforementioned drivetrain. Failure of the differential pressure feedback EGR and differential speed sensors (with related wiring) are occasional problems of the 2002 vehicles, and repair costs will vary depending on the extent of the wiring problems.
Other problems unique to the 2002 Mountaineers include the fuel gauge. It can drop to empty on vehicles with 4.0-liter engines, due to a flex fuel module problem that needs to be fixed. Another issue is fuel pump cavitation, which causes stumbling or hesitation (redesigned parts are available) and loose rear window glass (dealers can reposition the brackets and tighten the screws).
Problems with third-generation Mercury Mountaineers include dragging and overheating brakes (can be fixed by either removing them from a wiring harness or replacing a brake switch), coolant leaks on vehicles with 4.0- and 4.6-liter engines (solved with replacement hose clamps) and steering noise (fixed with steering column intermediate shaft replacement). Also, the shifter on the transmission of some third-generation vehicles may not come out of park, which can be solved by removing grease from the shift lockout switch.
