Jeep›Wrangler›2003›4.0L/jeep/wrangler/2003/4-0l/

TJ platform

2003 Jeep Wrangler — 4.0L

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2003 Wrangler 4.0L.

Body SUVEngine 4.0LTransmission Automatic 4-spd

The 2003 Jeep Wrangler 4.0L is a TJ-platform SUV powered by the 4.0L engine and paired with an automatic four-speed transmission, carrying EPA fuel-economy ratings of 14/18/16 mpg and a 6-quart 5W-30 API oil capacity with filter. Within the 1990–2023 Wrangler complaint record, this model year accounts for 102 owner complaints and 4 recalls, a volume that sits well below the 2018 peak of 1,793 complaints yet far above the 1996 low of 5. Power Train issues lead the complaint categories, so this year reads as a moderate-complaint TJ whose documented owner-reported concerns cluster most heavily in that area.

Model year2006 2005 2004 2003 2001 2000 1999 1998 1997

Quick specs

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

Engine oil capacity6 qt w/ filterOEM · verified

Engine oil type5W-30 APIOEM · verified

Lug nut torque85-110 ft-lbsOEM · verified

EPA fuel economy14/18/16 mpgEPA · verified

Fitment & sizes

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

From the factory this vehicle uses a BCI 34 · 600 CCA battery, OE oil filter 05281090AB. Note the factory fuel filter and front wiper blades are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. 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 34 · 600 CCAOEM · verified

Tire sizeLT245-75R16OEM · verified

Wheel / rim8 inOEM · verified

OE service part numbers OEM · verified

Engine oil filter	05281090AB alt 04105409AE
Engine air filter	04797777AC alt 05019443AA
Fuel filter	04798301 discontinued
Spark plug	SP000ZFR5N alt 68307021AA
Battery	1BPB5800AA
Front wiper blades	55154762AF discontinued
Serpentine belt	04854033AC alt 05281351AC
Thermostat	52028186AC alt 53010552AC

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic 4-spd

Ratings & economy EPA / vPIC

EPA city / highway / combined	14 / 18 / 16 mpg
Drivetrain	4-Wheel or All-Wheel Drive
Recommended fuel	Regular Gasoline

Performance & power Independent road tests

0–60 mph, quarter-mile, horsepower and torque from independent road tests.

Independent published road-test results.

9.8 sec0–60 mph (tested)quickest 9.80 sec — 2003 Rubicon 2-door

190 hpHorsepower (as tested)

235 lb-ftTorque (as tested)

Year	Trim / engine	0–60	¼ mile	HP	Drivetrain
2003	Rubicon 2-door 4.0L I-6	9.80 sec	17.30 sec	190 hp	4x4
1999	Sport 2-door 4.0L I-6	9.30 sec	17.10 sec	181 hp	4x4
1997	Sport 2-door 4.0L I-6	7.60 sec	16.30 sec	181 hp	4x4
1997	Sport 2-door 4.0L I-6	9.10 sec	16.90 sec	181 hp	4x4

Service quick specs OEM factory data

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

This engine holds 6 qt w/ filter of 5W-30 API engine oil, 80W-90 · GL-5 · SYNTHETIC in the differential, DOT 3 brake fluid. Torque lug nuts to 85-110 ft-lbs, the oil drain plug to 25.0 ft-lbs. The firing order is 1-5-3-6-2-4.

Lubricants & capacities

Brake Fluid	DOT 3
Differential Gear Oil	80W-90 · GL-5 · SYNTHETIC
Differential Gear Oil Capacity	4 pints, mvc front, non_mvc 216
Engine Coolant	HOAT · MS9769
Engine Oil	5W-30 · API
Engine Oil Capacity	6 qt w/ filter
Power Steering Fluid	MS-5931

Engine torques

Connecting Rod (Large End) Bearings	33-35 ft-lbs
Crankshaft Pulley and/or Damper Bolts	100 ft-lbs
Engine Oil Pan Drain Plug	25.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs	Pump bolts: 14 ft-lbs, Cover bolts: 9 ft-lbs

Chassis torques

Lug Nuts	85-110 ft-lbs
Transfer Case Fill Plug	Steel case: 35.0, Aluminum case: 18.0 ft-lbs
Transfer Case Drain Plug	Steel case: 35.0, Aluminum case: 18.0 ft-lbs
Front Wheel Hub	175 ft-lbs

Ignition

Cylinder Firing Order	1-3-4-2
Cylinder Firing Order	1-5-3-6-2-4
Ignition Coil Primary Resistance	.71-.88 ohms
Ignition Coil Secondary Resistance	11,300-13,300 ohms
Spark Plug Manufacturer	Champion
Spark Plug Gap	0.040 in
Spark Plug Torque	22.0 ft-lbs

Battery & A/C

Refrigerant	R134a
Refrigerant Capacity	1.25 lbs
Oil Group	PAG
Oil Type	ND 8 oil
Oil Capacity	6.10 oz
Standard BCI Group Number	34
Standard BCI Cranking Performance	600 cca

Service checks

Pressure Test	18 psi
Radiator Cap Pressure Relief	12-18 psi
Thermostat Opening Temperature	195 °F
Regulated Fuel System Pressure (With Vacuum)	47-51 psi
Engine Compression	120-150 PSI. 30 Maximum variation PSI.
Engine Oil Pressure	13
Intake Valve Lash	Hydraulic in
Exhaust Valve Lash	Hydraulic in

Brakes

Torque Caliper to Bracket	11 ft-lbs / 18 ft-lbs
Minimum Pad Thickness	0.030 in
Minimum Shoe Thickness	0.030
Rotor Max Parallel Variation	0.0005 in / 0.0007 in
Rotor Runout Limit	0.005 in / 0.004 in
Rotor Nominal Thickness From	0.94 in / 0.472 in
Rotor Nominal Thickness To	0.94 in / 0.472 in
Rotor Minimum Machining	0.894 in / 0.433 in

Multi-step torque procedures OEM · verified

Cylinder Head — tightening sequence 4 stages

Prep Coat threads of left hand front bolt with sealant

1	22 ft. lbs.	22 ft. lbs
2	45 ft. lbs.	45 ft. lbs
3	all bolts except L.H. front bolt	110 ft. lbs
4	100

Main Bearings — tightening sequence 7 stages

1	caps 1, 2, 4, 5, 6, and 7	40 ft. lbs
2	caps 1, 2, 4, 5, 6, and 7	70 ft. lbs
3	caps 1, 2, 4, 5, 6, and 7	80 ft. lbs
4	Push the crankshaft forward and backward. Load the crankshaft front or rear and tighten cap bolt No.3 to 40 ft. lbs.	40 ft. lbs
5	Tighten to 70 ft. lbs.	70 ft. lbs
6	Tighten to 80 ft. lbs.	80 ft. lbs
7	Rotate the crankshaft after tightening each main bearing cap to ensure the crankshaft rotates freely.

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 6,000 mi; spark plugs every 30,000 mi; coolant at 102,000 mi. The big-interval services (at 102,000 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 6,000 mi	Engine Oil (drain & refill) · Engine Oil Filter (replace) · Steering Linkage (inspect) · Tie Rod (inspect)
Every 7,500 mi	Tire & Wheel Assembly (rotate)
Every 15,000 mi	Accessory Drive Belt (inspect) · Suspension Ball Joint (inspect)
Every 18,000 mi	Brake Linings (inspect)
Every 30,000 mi	Engine Air Filter Element (replace) · Spark Plugs (inspect) · Spark Plugs (replace)
At 60,000 mi	Accessory Drive Belt (inspect) · Spark Plugs (inspect)
At 102,000 mi	Bands (adjust) · Engine Coolant System (drain, flush & refill) · Transmission Fluid & Filter (replace)
At 120,000 mi	Transfer Case Assembly (drain & refill)

Owner how-tos

Condensed service procedures for routine maintenance. Procedures that require dealer diagnostic equipment are identified and summarized only.

Common procedures

Key fob — remote (RKE) programming programming new fob buttons Dealer tool OEM · verified

Tool required	DRBIII scan tool (dealer / locksmith)
Why	Transmitter codes are written into the receiver in the passenger door module

Anti-theft (SKIS) — module initialization after immobilizer module replacement Dealer tool OEM · verified

When needed	After Sentry Key Immobilizer Module (SKIM) replacement
Tool required	DRBIII scan tool
Also required	The vehicle's four-digit PIN code

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 Jeep Wrangler recorded 102 complaints, 4 recalls, 0 investigations and 55 TSBs, which is slightly lower than the 108 complaints and 6 recalls in 2002 and markedly lower than the 192 complaints and 3 recalls in 2004. Looking at the broader trend, complaints rose sharply in the mid‑1990s, spiked again from 1997 through 2000, then fell to a trough in the early 2000s before climbing again after 2004. Thus, 2003 sits on the declining side of that early‑2000s dip, just before the complaint volume begins its next upward trajectory. The most frequent complaint areas for 2003 were Power Train (16), Suspension (11), Steering (7) and Fuel System, Gasoline (7), with 8 crash‑related and 3 fire‑related complaints reported. Taken together, the comparatively low complaint and recall counts suggest that 2003 is a relatively favorable model year to consider, though a buyer should still scrutinize the power train, suspension, steering and fuel‑system components.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

102

Owner complaints

8 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 ’12 ’13 ’14 ’15 ’16 ’17 ’18 ’19 ’20 ’21 ’22 ’23

Owner complaints filed with NHTSA, by component

All 102 complaints on record, top 8 components.

Power Train16

Suspension11

Steering7

Fuel System, Gasoline7

Air Bags6

Steering,Suspension6

Seat Belts6

Electrical System5

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 4 campaigns on record for this vehicle.

06E022000Service Brakes, HydraulicReported 13/03/2006

CERTAIN AFTERMARKET BRAKE HYDRAULIC MASTER CYLINDERS SOLD AS REPLACEMENT BRAKE CYLINDERS FOR CERTAIN FORD, DAIMLERCHRYSLER, AND JEEP PASSENGER VEHICLES. THESE BRAKE CYLINDERS WERE SOLD UNDER THE BRAND NAMES OF NAPA… Remedy: AFFINIA (BRAKE PARTS, INC.) WILL REPLACE THE SUBJECT BRAKE HYDRAULIC MASTER CYLINDERS FREE OF CHARGE. THE RECALL BEGAN ON MARCH 20, 2006. OWNERS CAN CONTACT AFFINA GROUP CUSTOMER…

06E026000Exterior LightingReported 23/03/2006

CERTAIN PRO-A MOTORS CORNER LAMPS, TURN SIGNALS, AND HEADLIGHTS SOLD AS REPLACEMENT LAMPS FOR USE ON CERTAIN PASSENGER VEHICLES LISTED ABOVE. SOME COMBINATION LAMPS THAT ARE NOT EQUIPPED WITH AMBER SIDE REFLECTORS FAIL… Remedy: PRO-A MOTORS WILL NOTIFY OWNERS AND OFFER TO REPURCHASE THE LAMPS. THE RECALL BEGAN ON APRIL 3, 2006. OWNERS MAY CONTACT PRO-A MOTORS AT 323-838-2988.

Technical service bulletins NHTSA · verified

Showing 5 of 55 bulletins on record with NHTSA.

Bulletin	Date	Component	Summary
101232	2024-10-29	Power Train	Plate - Planetary
9004275	2020-07-22	Electrical System	KEY, Master If replacing the key/FOBIK on a WJ, KJ, TJ, or PT Cruiser, use the "AC" NIC…
9004275	2020-07-22	Electrical System	KEY, Master If replacing the key/FOBIK on a WJ, KJ, TJ, or PT Cruiser, use the "AC" NIC…
S2025000005	2020-06-01	Electrical System	Malfunction Indicator Lamp (MIL) Illumination. Diagnostic Trouble Codes P0407 ? EGR…
23-015-20	2020-04-30	Equipment	Disinfectant Solution Recommended for COVID-19

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 Wrangler. 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 34 battery Vehicles taking 6 qt w/ filter TJ-platform vehicles Engine oil filter 05281090AB Engine air filter 04797777AC Fuel filter 04798301 Spark plug SP000ZFR5N

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 Wrangler 4.0L take?

6 qt w/ filter of 5W-30 API, per the factory manual.

Does the 2003 Wrangler have open recalls?

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

What gas mileage does the 4.0L get?

EPA figures are 14 city / 18 highway / 16 combined mpg.