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2003 Mercury Grand Marquis

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2003 Grand Marquis.

Body PASSENGER CARTransmission Automatic 4-spd

The 2003 Mercury Grand Marquis is a passenger car equipped with a 4-speed automatic transmission and an EPA rating of 16/23/18 mpg. This model utilizes 5W-20 API engine oil with a 6.0-quart capacity. With 395 total owner complaints—chiefly regarding exterior lighting—and two recalls, this year sits within a 1990-2011 model history that peaked at 487 complaints in 2005 and reached a low of 9 in 2011.

Model year2011 2010 2009 2008 2007 2006 2005 2004 2003

Quick specs

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

Engine oil capacity6.0 qtOEM · verified

Engine oil type5W-20 APIOEM · verified

Lug nut torque85-105 ft-lbsOEM · verified

EPA fuel economy16/23/18 mpgEPA · verified

Fitment & sizes

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

From the factory this vehicle uses a BCI 65 · 650 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 65 · 650 CCAOEM · verified

Tire sizeP225-60TR16OEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic 4-spd

Ratings & economy EPA / vPIC

EPA city / highway / combined	16 / 23 / 18 mpg
Drivetrain	Rear-Wheel Drive
Passenger volume	109 cu ft
Cargo volume	21 cu ft
Recommended fuel	Regular Gasoline

Service quick specs OEM factory data

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

This engine holds 6.0 qt of 5W-20 API engine oil, DOT 3 brake fluid. Torque lug nuts to 85-105 ft-lbs, the oil drain plug to 19.0 ft-lbs. The firing order is 1-3-7-2-6-5-4-8. 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

Brake Fluid	DOT 3
Engine Oil	5W-20 · API
Engine Oil Capacity	6.0 qt
Power Steering Fluid	ATF

Engine torques

Intake Manifold to Engine Bolts	18.0 ft-lbs
Exhaust Manifold to Cylinder Head Bolts	18.0 ft-lbs
Engine Oil Pan Drain Plug	19.0 ft-lbs

Chassis torques

Lug Nuts

85-105 ft-lbs

Ignition

Cylinder Firing Order	1-3-7-2-6-5-4-8
Curb Idle Speed (No Load)	802.5 rpm
Curb Idle Speed Variance (No Load)	12.5 rpm
Spark Plug Manufacturer	Motorcraft
Spark Plug Gap	0.052-0.056 in
Spark Plug Torque	11.0 ft-lbs
Ignition Timing	10, Not adjustable degrees
Ignition Timing Acceptable Variance	2 degrees

Battery & A/C

Refrigerant	R134a
Refrigerant Capacity	2.38 lbs
Oil Group	PAG
Oil Type	46
Oil Capacity	7.50 oz
Standard BCI Group Number	65
Standard BCI Cranking Performance	650 cca
Optional BCI Group Number	65

Service checks

Pressure Test	13-18 psi
Radiator Cap Pressure Relief	13-18 psi
Thermostat Opening Temperature	192-199 °F
Key ON Engine OFF (KOEO)	30.0-50.0
Engine Oil Pressure	40-70 psi
Engine Oil Pressure RPM	2500 rpm
Intake Valve Lash	Hydraulic in
Exhaust Valve Lash	Hydraulic in

Brakes

Torque Caliper to Bracket	118 ft-lbs / 18 ft-lbs
Torque to Knuckle	100 ft-lbs / 50 ft-lbs
Minimum Pad Thickness	Front: 0.039; Rear: 0.039 in
Minimum Shoe Thickness	0.154 in
Rotor Runout Limit	0.003 in
Rotor Minimum Machining	1.063 in / 0.732 in
Rotor Discard at or Under	1.037 in / 0.708 in

Multi-step torque procedures OEM · verified

Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages

37 ft. lbs., step 2: 90

37 ft. lbs

Cylinder Head — tightening sequence 6 stages

Prep Do not reuse old bolts. Coat bolt threads with clean engine oil.

1	30.0 ft. lbs.	30 ft. lbs
2	90 degrees	90 degrees
3	Loosen bolts 360 degrees	360 degrees
4	30.0 ft. lbs.	30 ft. lbs
5	90 degrees	90 degrees
6	90 degrees	90 degrees

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 5,000 mi; spark plugs every 100,000 mi; coolant every 30,000 mi. The big-interval services (every 30,000 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 5,000 mi	Engine Oil (drain & refill) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
Every 15,000 mi	Brake System (inspect) · Cabin Air Filter (replace) · Engine Coolant System (leak inspection) · Steering Linkage (inspect) · Suspension System (inspect) · Wheel Bearing (inspect)
Every 30,000 mi	Engine Air Filter Element (replace) · Engine Coolant System (drain, flush & refill) · Exhaust System Heat Shield (inspect) · Fuel Filter (replace)
At 45,000 mi	Engine Coolant System (drain, flush & refill)
Every 100,000 mi	Accessory Drive Belt (inspect) · PCV Valve (replace) · Spark Plugs (replace)
At 150,000 mi	Drive Axle Assembly (drain & refill) · Transmission Fluid & Filter (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 2003 Mercury Grand Marquis marks a sharp inflection point in the model's federal complaint record: complaints jumped from 106 in 2002 to 395 in 2003, surpassing the 1997 peak of 383 and helping initiate a late-generation surge that peaked at 487 complaints in 2005. While recalls held steady at two, matching 2002 and 2004, NHTSA investigations rose sharply from one in 2002 to six in 2003, and technical service bulletins increased from 67 to 90. Exterior lighting dominated the 2003 complaint profile with 173 reports, followed by electrical/exterior lighting cross-codes, steering, and suspension; the data does not specify root causes. The 26 crash-related and three fire-related complaints are present but represent small shares of the total complaint volume. Viewed against the broader arc, 2003 sits at the front edge of the generation's worst complaint period rather than in a quiet mid-cycle stretch. Given the sudden spike in owner complaints and investigations alongside low recall activity, this is a riskier year to buy than the immediately preceding 2002 model and not the strongest choice within this generation.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

395

Owner complaints

26 involved a crash · 3 a fire

NHTSA crash-test rating federal NCAP · out of 5 stars

Rollover★★★★★

Owner complaints by model year NHTSA · this generation & adjacent

’90 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’01 ’02’03’04 ’05 ’06 ’07 ’08 ’09 ’10 ’11

Owner complaints filed with NHTSA, by component

All 395 complaints on record, top 8 components.

Exterior Lighting173

Electrical System,Exterior Lighting25

Steering25

Suspension21

Vehicle Speed Control21

Electrical System14

Engine & Engine Cooling12

Structure10

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 2 campaigns on record for this vehicle.

15V861000Exterior Lighting:HeadlightsReported 22/12/2015

Ford Motor Company (Ford) is recalling certain model year 2003-2005 Ford Crown Victoria and Mercury Grand Marquis vehicles manufactured October 3, 2001, to August 2, 2005. The affected vehicles have a lighting control… Remedy: Ford will notify owners, and dealers will replace the LCM, free of charge. The recall began April 14, 2017. Owners may contact Ford customer service at 1-866-436-7332. Ford's…

06E056000Fuel System, GasolineReported 13/06/2006

CERTAIN AFTERMARKET FUEL FILTERS SOLD UNDER THE PUROLATOR BRAND NAME, P/N F65277, SHIPPED FROM JANUARY 16 THROUGH JUNE 2, 2006, FOR USE ON THE ABOVE LISTED PASSENGER VEHICLES. DUE TO INCORRECT DESIGN, THE QUICK… Remedy: UFI WILL NOTIFY OWNERS AND REPLACE THE FILTERS FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 4, 2006. OWNERS MAY CONTACT UFI FILTERS USA AT 800-230-5876.

Technical service bulletins NHTSA · verified

Showing 5 of 90 bulletins on record with NHTSA.

Bulletin	Date	Component	Summary
TSB 19-2026	2019-02-07	Structure	Some 2000 and newer Ford, Lincoln and Mercury vehicles equipped with aluminum body panels…
TSB 19-2026	2019-02-07	Structure	Some 2000 and newer Ford, Lincoln and Mercury vehicles equipped with aluminum body panels…
ASI-45182	2015-06-01	Electrical System	SUMMARY TO BE PROVIDED ON A FUTURE DATE.
CSP-14N01	2014-04-11	Equipment	FORD: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. INFORMATION REGARDING THE LIGHTING…
CSP-14-N-01	2014-04-11	Exterior Lighting	FORD: THE LIGHTING CONTROL MODULE HAS EXTENDED WARRANTY COVERAGE, ON CERTAIN VEHICLES…

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 Grand Marquis. 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.

Group 65 battery Vehicles taking 6.0 qt

Reference guides

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

Vehicle recalls & TSBs OBD-II trouble codes Torque specifications Maintenance schedules Fluid capacities & specs

Frequently asked

How much oil does the 2003 Grand Marquis take?

6.0 qt of 5W-20 API, per the factory manual.

Does the 2003 Grand Marquis have open recalls?

NHTSA lists 2 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Grand Marquis get?

EPA figures are 16 city / 23 highway / 18 combined mpg.