MercuryMariner2008Overview/mercury/mariner/2008/base/

2008 Mercury Mariner

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2008 Mariner.

Body SUV

The 2008 Mercury Mariner is a compact SUV that, under the hood, requires 4.5 quarts of 5W-20 API-grade engine oil. Notably, this model year generated 461 owner complaints—the highest count across the Mariner’s 2001–2011 production span—with steering identified as the top problem area, alongside four official recalls. In the model’s reliability history, the 2008 Mariner stands as the most complaint-prone year, contrasting sharply with the 2007 model’s low of just 33 complaints, marking it as a year to scrutinize closely for steering-related issues.

Model year2011201020092008200720062005

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.5 qtOEM · verified
Engine oil type5W-20 APIOEM · verified
Lug nut torque100 ft-lbsOEM · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 40R · 590 CCA battery. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 40R · 590 CCAOEM · verified
Tire sizeP235-70R16OEM · verified

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.5 qt of 5W-20 API engine oil, DOT 3 brake fluid. Torque lug nuts to 100 ft-lbs, the oil drain plug to 18.0 ft-lbs. The firing order is 1-4-2-5-3-6. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

Automatic Transmission FluidFord Mercon LV
Automatic Transmission Fluid Capacity5
Brake FluidDOT 3
Engine CoolantUSE FORD PREMIUM GOLD COOLANT
Engine Oil5W-20 · API
Engine Oil Capacity4.5 qt
Engine Oil5W-20 · API
Engine Oil Capacity6.0 qt

Engine torques

Intake Manifold to Engine Bolts13 ft-lbs
Exhaust Manifold to Cylinder Head Bolts35 ft-lbs
Intake Manifold to Engine Bolts7.4 ft-lbs
Exhaust Manifold to Cylinder Head Bolts15 ft-lbs
Engine Oil Pan Drain Plug21.0 ft-lbs
Engine Oil Pan Drain Plug21.0 ft-lbs
Engine Oil Pan Drain Plug18.0 ft-lbs

Chassis torques

Lug Nuts100 ft-lbs
Transfer Case Fill PlugAT: 25.0, MT: 35.0 ft-lbs
Transfer Case Drain Plug10.0 ft-lbs
Front Wheel Hub222 ft-lbs
Rear Wheel Hub221 ft-lbs

Ignition

Cylinder Firing Order1-3-4-2
Cylinder Firing Order1-4-2-5-3-6
Spark Plug ManufacturerMotorcraft
Spark Plug Gap0.049-0.053 in
Spark Plug Torque9.0 ft-lbs

Battery & A/C

RefrigerantR134a
Refrigerant Capacity1.57 lbs
Oil GroupPAG
Oil Type46
Oil Capacity5.00 oz
RefrigerantR134a
Refrigerant Capacity2.00-2.56 lbs
Standard BCI Group Number40R

Service checks

Pressure Test20 psi
Radiator Cap Pressure Relief17-21 psi
Thermostat Opening Temperature194 °F
Pressure Test20 psi
Radiator Cap Pressure Relief17-21 psi
Thermostat Opening Temperature183-190 °F
Key ON Engine OFF (KOEO)39
RPM39 @ Idle rpm

Brakes

Torque Caliper to Bracket37 ft-lbs
Torque to Knuckle129 ft-lbs
Minimum Pad ThicknessFront: 0.118; Rear: 0.118 in
Minimum Pad ThicknessFront: 0.118; Rear: 0.118 in
Minimum Shoe Thickness0.039 in
Rotor Runout Limit0.002 in
Rotor Discard at or Under0.944 in
Drum Discard at-or-over10.09

Multi-step torque procedures OEM · verified

Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 1 stages
15 ft. lbs., Step 2: 12.15 ft. lbs
Connecting Rod (Large End) Bearings — tightening sequence 1 stages
121 ft. lbs., Step 2: 9021 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
174 ft. lbs., step 9074 ft. lbs
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
189 ft. lbs., step 2: 360 degrees, step 4: 37 ft. lbs., step 5: 9089 ft. lbs
Cylinder Head — tightening sequence 5 stages
13.7 ft. lbs.3.7 ft. lbs
211 ft. lbs.11 ft. lbs
333 ft. lbs.33 ft. lbs
490 degrees90 degrees
590
Cylinder Head — tightening sequence 5 stages
13.7 ft. lbs.3.7 ft. lbs
211 ft. lbs.11 ft. lbs
333 ft. lbs.33 ft. lbs
490 degrees90 degrees
590
Cylinder Head — tightening sequence 5 stages
1Tighten in sequence shown 5.17 ft. lbs.5.17 ft. lbs
2Tighten in sequence shown 11 ft. lbs.11 ft. lbs
3Tighten in sequence shown 33 ft. lbs.33 ft. lbs
490 degrees90 degrees
590
Cylinder Head — tightening sequence 6 stages
1Tighten in sequence shown 30 ft. lbs.30 ft. lbs
290 degrees90 degrees
3loosen one complete turn
4Tighten in sequence shown 30 ft. lbs.30 ft. lbs
590 degrees90 degrees
690
Engine Flywheel Bolts — tightening sequence 1 stages
137 ft. lbs., Step 2: 59 ft. lbs., Step 3: 8337 ft. lbs
Main Bearings — tightening sequence 1 stages
14 ft. lbs., Step 2: 18 ft. lbs., Step 3: 904 ft. lbs
Oil Pump to Cylinder BLock Bolts/Studs — tightening sequence 1 stages
17 ft. lbs., Step 2: 157 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs every 100,000 mi; coolant every 50,000 mi. The big-interval services (every 50,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 7,500 miEngine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
Every 10,000 miHybrid Battery Compartment Air Filter (inspect)
Every 15,000 miBrake System (inspect) · Cabin Air Filter (replace) · Engine Coolant System Hoses (inspect) · Steering Linkage (lubricate) · Suspension System (inspect) · Transmission Assembly (inspect fluid level)
Every 20,000 miSuspension Ball Joint (inspect)
Every 30,000 miEngine Air Filter Element (replace) · Exhaust System (Complete) (inspect) · Fuel Filter (replace) · Temperature Controlled Seat Air Filter (replace)
Every 50,000 miEngine Coolant System (drain, flush & refill)
At 100,000 miEngine Coolant System (drain, flush & refill)
Every 100,000 miAccessory Drive Belt (inspect) · PCV Valve (replace) · Spark Plugs (replace)
At 150,000 miDrive Axle Assembly (drain & refill) · Drive Belt (replace) · Transfer Case Assembly (drain & refill) · Transmission Fluid & Filter (replace) · Wheel Bearing (replace)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 2008 Mercury Mariner marks a dramatic inflection point in the model’s federal record, with owner complaints surging to 461 from just 33 in 2007 and far exceeding the 63-to-67 range observed in 2005 and 2006. This model year sits at the absolute peak of the generational arc, posting the highest complaint volume of any year in the dataset along with four recalls and two investigations, within a generation that otherwise showed modest federal activity through 2004 and tapering reports after 2008. Steering dominates the 2008 record with 262 complaints, followed by power train at 46 and service brakes at 23, though the data does not specify root cause; the year also generated nine crash-related complaints and zero fire complaints. While 2009 and 2010 saw volumes decline to 315 and 278 complaints respectively, 2008 remains the clear statistical outlier. Because this year carries the most severe concentration of reported problems and sits at the apex of a pronounced spike, it is the least favorable model year in this generation to purchase.

4
Open recalls
NHTSA campaigns
31
Service bulletins
Manufacturer communications
2
ODI investigations
Office of Defects Investigation
461
Owner complaints
9 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Rollover★★★★★
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 461 complaints on record, top 8 components.

Steering262
Power Train46
Service Brakes23
Vehicle Speed Control16
Unknown Or Other11
Steering,Electrical System11
Air Bags7
Service Brakes, Hydraulic5

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 4 campaigns on record for this vehicle.

15E045000Suspension:Front:Wheel BearingReported 03/06/2015

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… Remedy: Timken has begun notifying distributors who will offer purchasers replacement wheel bearings, free of charge. The recall began on May 21, 2015. Owners may contact Timken customer…

15V606000Power Train:Automatic Transmission:Lever And Linkage:Floor ShiftReported 29/09/2015

Ford Motor Company (Ford) is recalling certain model year 2001-2008 Ford Escape and Mercury Mariner vehicles manufactured March 31, 2001, to September 1, 2009. The affected vehicles are equipped with either a 2.3L or… Remedy: Ford will notify owners, and dealers will inspect the transmissions and either tighten the manual shift lever bolt or replace the manual shift lever assembly. These repairs will…

Technical service bulletins NHTSA · verified

Showing 5 of 31 bulletins on record with NHTSA.

BulletinDateComponentSummary
SSM 472012018-03-30EquipmentReplacing the original equipment SYNC/Navigation system with either an aftermarket…
SSM 470092018-01-10EquipmentThe Accessory (Wireless) Keyless Entry Keypad can only be used with vehicles that are…
SSM 470092018-01-10EquipmentThe Accessory (Wireless) Keyless Entry Keypad can only be used with vehicles that are…
SSM 463322017-01-24EquipmentREPLACING THE ORIGINAL EQUIPMENT SYNC/NAVIGATION SYSTEM WITH EITHER AN AFTERMARKET…
SSM 460852016-09-21Engine And Engine CoolingThe Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Mariner. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 2008 Mariner take?

4.5 qt of 5W-20 API MEETING FORD SPECIFICATION WSS-M2C945-A, per the factory manual.

Does the 2008 Mariner have open recalls?

NHTSA lists 4 recall campaign(s) for this model year. Check your specific vehicle by VIN.