Is the 2009 Mercury Mariner a bad year?
315 owner complaints to NHTSA. Engine complaints: 60, 6× a quiet Mariner year.
Keep it, but watch the engine
Half of the engine complaints for this year were filed at 46k–90k miles, where you are now.
The verdict moves with mileage: the same car reads differently at 30,000 and at 150,000 miles.
What 2009 Mariner owners report, by mileage
Each system owners named in five or more complaints, with the mileage range where the middle half of those complaints were filed. Read at 69,000 miles.
| SYSTEM | COMPLAINTS | MIDDLE HALF FILED AT | TYPICAL US REPAIR BILLS |
|---|---|---|---|
| EngineSTANDS OUT | 60 (19%) | 46k–90k miles · around this mileage | Valve cover gasket replacement $110–$500 · Timing chain replacement $1,000–$4,000 |
| Transmission and drivetrainSTANDS OUT | 44 (14%) | 45k–95k miles · around this mileage | CV axle / CV joint replacement (one side) $300–$1,500 · Automatic transmission replacement $2,500–$7,000 |
| Speed controlSTANDS OUT | 41 (13%) | 48k–97k miles · around this mileage | — |
| SteeringSTANDS OUT | 167 (53%) | 100k–148k miles · ahead | Steering rack and pinion replacement $700–$2,100 |
| Fuel system | 30 (10%) | 58k–102k miles · around this mileage | Fuel pump replacement $220–$1,500 · Fuel injector replacement (one injector) $300–$1,200 |
| Electrical system | 22 (7%) | 52k–120k miles · around this mileage | 12-volt battery replacement $100–$400 · Starter motor replacement $350–$1,200 |
| Brakes | 14 (4%) | 66k–122k miles · around this mileage | Brake pad replacement (one axle) $115–$390 · Brake pads and rotors replacement (one axle) $200–$1,084 |
| Wheels | 7 (2%) | too few with a mileage | — |
Bills are typical US ranges from the sources named in the tool (J.D. Power, Kelley Blue Book, CarParts.com and others), printed only for systems that stand out or sit at or ahead of 69,000 miles. Not a quote.
What owners reported alongside their complaints
Of 315 complaints: 9 mention a crash · 3 report an injury · 6 say the car was towed.
4 complaints were filed in the last 12 months, the newest in Apr 2026.
Counts of what owners wrote in their complaints, not verified by anyone.
In owners' own words
While driving the auto just stopped and the check engine light came on and stayed on. I turned the auto off and restarted.
2009 Mercury mariner with about 90,000 miles. Was on the freeway driving about 65-70 MPH when suddenly the power to car cut off - was not able to accelerate vehicle; drove to right side of the road.
When being aggressive with the accelerator the engine stalls and the accelerator stops working forcing the driver to pull off of the road.
Unedited excerpts from complaints filed with NHTSA, chosen by mileage (nearest 69,000 miles), not by content. Unverified.
Recalls for the 2009 Mercury Mariner: 2
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. Use of an incorrectly sized wheel bearing can adversely affect the braking and steering of the vehicle, increasing the risk of a crash.
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. If power steering assist is lost, greater driver effort would be required to steer the vehicle at low speeds, increasing the risk of a crash.
A recall may cover only some cars of a model year; the campaign size counts every model and year it lists. Enter your VIN at nhtsa.gov/recalls: dealers fix open recalls free.
Service bulletins from Mercury: 27
Repair instructions Mercury sent its dealers for symptoms seen in the shop on the 2009 Mercury Mariner. Ask a dealer or mechanic for a bulletin by its number.
In valve body, a worn solenoid pressure regulator valve has diagnostic trouble code (DTC) P0735 stored and indication of repair history was the valve body was…
Mercury/ford: on some vehicles, there is a fluid leakage, coming from left hand (Lh) halfshaft seal of the automatic transmission and a service kit…
Due to an intermittent loss of RPM or lack of acceleration, in some vehicles, with illuminated wrench light, diagnostic trouble codes (DTCs) P2111…
On the left hand half shaft seal, there is a fluid leak from the transmission because of wear on case bushing
NHTSA defect investigations: 2
Loss of power steering while driving
Electronic Throttle Body Malfunction
Neighbouring years
2008 Mariner: 461 complaints, keep it, but watch the transmission · 2010 Mariner: 270 complaints, keep it, but watch the engine.
Every Mercury Mariner year
2005 · 2006 · 2007 · 2008 · 2009 · 2010 · 2011 · All Mariner years side by side
Other Mercury models: Mercury Cougar · Mercury Grand Marquis · Mercury Mariner Hybrid · Mercury Milan · Mercury Montego · Mercury Monterey · Mercury Mountaineer · Mercury Sable. All makes and models.
Questions
Is the 2009 Mercury Mariner a bad year?
315 owner complaints to NHTSA. Engine complaints: 60, 6× a quiet Mariner year. At 69,000 miles the tool says: Keep it, but watch the engine. Half of the engine complaints for this year were filed at 46k–90k miles, where you are now.
What are the most common problems with the 2009 Mercury Mariner?
By owner complaints to NHTSA: engine (60), transmission and drivetrain (44), speed control (41), steering (167), fuel system (30). Half of the engine complaints were filed between 46k–90k miles.
How many recalls does the 2009 Mercury Mariner have?
2 recall campaigns list this model year: Suspension (NHTSA 15E045000), Steering (NHTSA 14V-284). A recall may cover only some cars; check by VIN at nhtsa.gov/recalls.
Method: counts of unverified owner complaints filed with NHTSA, compared only with other years of the same model (sales volumes are unknown, so no failure rate is computed). A system stands out at 40+ complaints and at least twice the model's quiet (lower-quartile) year, or twice the share across every vehicle of that model year. The mileage range is the 25th to 75th percentile of the mileages owners reported. Data received by NHTSA through November 5, 2026. Repair prices are typical US ranges from named sources, not quotes. Not a diagnosis and not financial advice. PulsCar is not affiliated with NHTSA. Check this car at your own mileage.