2009 Mercury Mariner - Maintenance & Specs
The 2009 Mercury Mariner belongs to a Mercury Mariner lineup that Know Your Ride tracks across 5 model years, from 2007 to 2011. Engine options on record include the 2.5L, 3.0L, 2.5L I4 / 3.0L V6. It is configured as front-wheel drive with an automatic 6-spd. The 2009 sits mid-run, with both earlier (2007) and later (2011) Mariner model years also documented.
It takes 5W-30 full synthetic oil, 4.5 qt with a new filter meeting API SP. Fluid specs on file include Motorcraft Orange coolant, DOT 3 brake fluid. Know Your Ride lists 14 scheduled maintenance items for this vehicle, the earliest interval falling at 7,500 miles. Documented torque values include oil drain plug 20 ft-lb, lug nut 80 ft-lb, spark plug 18 ft-lb.
NHTSA complaints for this vehicle cluster around steering (145), power train (17), engine (16). A representative report reads: "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..." There are 2 safety recalls on record; one covers: ...ling certain model year 2008-2011 Ford Escape and Mercury Mariner vehicles manufactured August 18, 2006, through September 11, 2010. The affected....
EPA fuel economy is rated at 20 city / 28 highway MPG, 23 MPG combined. Estimated annual fuel cost is about $1,900.
Quick Specs
| Oil viscosity | 5W-30 |
| Oil type | Full Synthetic |
| Oil capacity (w/ filter) | 4.5 qt |
| OEM oil spec | API SP |
| EPA combined | 23 MPG |
| Coolant | Motorcraft Orange |
| Open recalls on record | 2 |
| Technical service bulletins | 20 |
Common Trouble Codes
- P0300 - Random/Multiple Cylinder Misfire Detected
- P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
- P0171 - System too Lean (Bank 1)
- P0128 - Insufficient Coolant Temperature for Stable Operation
- P0442 - Evaporative Emission Control System Leak Detected (small leak)
- P0455 - Evaporative Emission Control System Leak Detected (gross leak)
- P0700 - Transmission Control System Malfunction
- P0301 - Cylinder 1 Misfire Detected
- U0100 - Lost Communication With ECM/PCM A
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Part of the free Know Your Ride vehicle maintenance reference. Figures are sourced from EPA, NHTSA and manufacturer data and are for general reference - always confirm with your owner's manual.