NHTSA lists 2 safety recalls and 315 owner complaints for the 2009 Mercury Mariner. Most complaints involve steering (167) and engine (53). The EPA rates it 20–23 mpg combined.
The Timken Company (Timken) is recalling certain aftermarket front wheel bearings, part number 510072, sold from January 22, 2015, to May 21, 2015, to be used as service parts on 2001-2012 Ford Escape, 2001-2011 Mazda Tribute, and 2005-2011 Mercury Mariner vehicles. The affected wheel bearings have incorrect dimensions of a 42mm bore, 76mm outer dimension, and 39mm width, instead of a 42mm bore, 78mm outer dimension and a 45mm width.
Ford Motor Company (Ford) is recalling certain model year 2008-2011 Ford Escape and Mercury Mariner vehicles manufactured August 18, 2006, through September 11, 2010. The affected vehicles have a steering torque sensor that may not be able to properly detect driver steering input. As a result, the system could remove the Electric Power Steering (EPS) assist.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“My vehicle was returned to me following a torque sensor replacement on 4/9/2026 in poor condition (locked steering and a catastrophic gash in the driver-side tire) rendering it undrivable and unsafe. Crossroads Ford of Prince George shop's inspection report claims the tire damage was pre-existing, I have conclusive evidence to the contrary: Virginia State Inspection: My vehicle passed a Virginia state safety inspection on 2/27/2026. Per state law, any tire with a gash or sidewall crack is an automatic failure. This legally certifies the tire was intact immediately prior to their service. Recent Tire Service: I replaced my rear tires at OK Tire and Auto on 3/30/2026. At that time, a full tread and sidewall inspection of my front tires confirmed they were in good condition. The timing of the dealership's communication confirms the damage occurred while in their care: I arrived for my 9:30a appointment around 9:25a. No damage was noted during the initial intake. I was in their facility when I watched a mechanic drive to the other side of the service parking lot without being informed of a "catastrophic" safety issue. I was only notified of the gash at the end of…”
“MY 2009 MERCURY MARINER (HAS 56,000 MILES), WITHOUT ANY WARNING, IT JUST SHUT OFF WHILE I WAS DRIVING IT. HAS HAPPENED TWICE. WAS ABLE TO GET THE SIDE OF THE ROAD AND WAS ABLE TO RESTART IT. NO WARNING LIGHTS CAME ON AT ALL. CAR IS AT DEALERSHIP NOW TO HAVE IT CHECKED OUT.”
“I have been intermittently losing power steering. The code is B1342. After researching, it looks like Ford is aware of this problem but is unwilling to fix the issue. This fix must be done at a dealership since it is a software issue and going to cost $2,000. Obviously losing power steering when going at fast speeds is incredibly dangerous for myself and others. There is no check engine light that comes on when the issue arises.”
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| Mariner FWD Auto 6-spd, 4 cyl, 2.5 L · Front-Wheel Drive | 20 | 28 | 23 | $2,700 | 386 |
| Mariner 4WD Auto 6-spd, 4 cyl, 2.5 L · 4-Wheel or All-Wheel Drive | 19 | 25 | 21 | $2,950 | 423 |
| Mariner FWD Auto 6-spd, 6 cyl, 3.0 L · Front-Wheel Drive | 18 | 26 | 21 | $2,950 | 423 |
| Mariner 4WD Auto 6-spd, 6 cyl, 3.0 L · 4-Wheel or All-Wheel Drive | 17 | 24 | 20 | $3,100 | 444 |
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
2 safety recalls as of Nov 10, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 315 complaints with NHTSA. The most-cited components are steering (167), engine (53), power train (44). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
The EPA rates the 2009 Mercury Mariner at 20–23 mpg combined, depending on engine and drivetrain (4 versions rated).