The 2003–2004 Toyota 4Runner 4WD (chassis code GRN215) launched the fourth generation of Toyota’s mid-size, body-on-frame SUV for North America. It pairs the all-new, chain-driven 1GR-FE 4.0-liter V6 with a robust 4-speed automatic and a multi-mode 4WD system that includes a lockable center differential and low range. Compared with the previous generation, the 4Runner moved to a stiffer 120-series frame, adopted an independent double-wishbone front suspension for better on-road control, and retained a solid rear axle for durability and towing stability. Inside, it emphasizes practical ergonomics, generous cargo space, and the signature roll-down rear glass. This guide focuses on the 2003–2004 V6 4WD variant: what it is, how it’s built, the specs that matter, common issues and recall pointers, maintenance planning with fluid specs and torque values, real-world driving impressions, and how it stacks up against rivals. If you need a comfortable highway cruiser that still offers genuine low-range capability and long-term dependability, the early fourth-gen 4Runner belongs on your shortlist.
Key Takeaways
- Proven 1GR-FE 4.0 V6 (245 hp) with a timing chain and multi-mode 4WD (2H/4H/open or locked/4L) for year-round, real-world traction.
- Ladder-frame strength, 5,000 lb (2,268 kg) towing, and good ground clearance make it versatile for towing, snow, and trail travel.
- Watch for frame/underbody corrosion, X-REAS shock leaks (Sport), and overdue driveline fluids—typical on older trucks.
- Routine interval: engine oil and filter every 5,000 mi (8,000 km) or 6 months with SAE 5W-30.
Navigate this guide
- Detailed Overview
- Specifications and Technical Data
- Trims and Options, Safety and Driver Assistance
- Reliability, Common Issues and Service Actions
- Maintenance and Buyer’s Guide
- Driving and Performance
- How 4Runner Compares to Rivals
Detailed Overview
The GRN215 designation identifies a V6-powered, four-wheel-drive 4Runner built on Toyota’s 120-series ladder frame. At its heart is the first-generation 1GR-FE 4.0-liter V6 with aluminum block and heads, dual overhead cams, and VVT-i on the intake side. It uses a timing chain rather than a belt, reducing scheduled maintenance and supporting high-mile longevity when oil changes are on time. In 2003–2004, this engine is paired with Toyota’s A340F 4-speed automatic—simple, durable, and well matched to the V6’s torque curve.
A major change from the third generation is up front: the move to independent double wishbones improves impact absorption and directional stability while preserving a solid, coil-sprung rear axle for articulation, payload, and towing control. Brakes are four-wheel discs with ABS and electronic brake-force distribution, while Vehicle Stability Control and A-TRAC (a brake-based traction aid) broaden all-weather confidence. Compared with crossovers, the 4Runner remains a true SUV—body-on-frame, low range, and cooling capacity aimed at towing or steep grades.
The multi-mode 4WD system is a highlight. In routine driving you can use 2H (rear-drive) for efficiency. When roads turn slick, 4H (with the center differential open) enables all-wheel traction on mixed-grip surfaces. Engaging the center-diff lock gives a fixed 50:50 torque split for uniform low-grip conditions like snow-covered roads. For technical trails, 4L multiplies torque for controlled crawling and steep descents. This flexibility makes the 4Runner easy to live with in varied climates without sacrificing real trail ability.
Inside, the fourth gen emphasizes durability and usability. Large rotary HVAC controls, intuitive switchgear, supportive seats, and a broad cargo floor make long days in the saddle easy. The power roll-down rear window is a distinctive 4Runner feature, offering quick bed access and ventilation. Trims span SR5 (value), Sport Edition (with the X-REAS cross-linked shock system to curb pitch and roll), and Limited (comfort and sound insulation). Properly set up with a weight-distributing hitch and fresh shocks, the 4Runner tows confidently to its 5,000-lb rating.
The 2003–2004 configuration is sought after for its simpler transmission, excellent parts availability, and strong aftermarket support. Shopping smart means vetting for corrosion, confirming 4WD operation in all modes, and budgeting a complete baseline of fluids if records are thin. Cared for, these trucks routinely exceed 200,000–300,000 miles of service.
Specifications and Technical Data
Engine and Performance
| Item | Detail |
|---|---|
| Engine code | 1GR-FE (VVT-i), aluminum block/heads, DOHC, chain-driven |
| Displacement | 4.0 L (3,956 cc) |
| Induction/fueling | Naturally aspirated, port fuel injection |
| Compression ratio | ~10.0:1 |
| Rated power | 245 hp (183 kW) @ ~5,200 rpm |
| Rated torque | 320 Nm (236 lb-ft) @ ~4,000 rpm |
| Fuel requirement | Regular unleaded 87 AKI (approx. 91 RON) |
| Fuel tank | 23.0 gal (87 L) |
| Emissions/OBD | OBD-II; period LEV-class |
| Aerodynamics (typical) | Cd ~0.36–0.37; frontal area ~2.6–2.7 m² |
Transmission and Driveline
| Item | Detail |
|---|---|
| Automatic | A340F 4-speed |
| Gear ratios (1→4 / Rev) | 2.804 / 1.531 / 1.000 / 0.705 ; Rev 2.393 |
| Final drive (typical) | ~3.91 (varies by axle code) |
| Transfer case | Multi-mode: 2H / 4H (open) / 4H (center diff locked) / 4L (locked) |
| Center differential | Lockable planetary |
| Traction aids | A-TRAC, Vehicle Stability Control (VSC), ABS/EBD, Brake Assist |
Chassis and Dimensions
| Item | Detail |
|---|---|
| Platform | 120-series body-on-frame |
| Front suspension | Double wishbone, coil springs, gas shocks |
| Rear suspension | Solid axle, 4-link with Panhard rod, coils |
| Steering | Rack-and-pinion, hydraulic assist |
| Brakes | 4-wheel discs (front ventilated) |
| Wheels/tyres | 16–18 in; common 265/70R16 or 265/65R17 |
| Length | ~4,750 mm (187.0 in) |
| Width (excl. mirrors) | ~1,875 mm (73.8 in) |
| Height | ~1,790 mm (70.5 in) |
| Wheelbase | 2,790 mm (109.8 in) |
| Ground clearance | ~235–245 mm (9.3–9.6 in) |
| Approach/departure | ~30° / ~26° (by bumper/trim) |
| Curb weight | ~1,900–2,050 kg (4,190–4,520 lb) |
| GVWR | ~2,675–2,800 kg (5,900–6,170 lb) |
| Turning circle | ~11.2 m (36.7 ft) |
| Cargo volume | ~1,330 L (47.0 ft³) seats up; ~2,210 L (78.0 ft³) seats down |
Fluids and Capacities
| System | Specification | Capacity (approx.) | Notes / Key torque values |
|---|---|---|---|
| Engine oil | SAE 5W-30, API SL or later | 5.5–5.7 L (5.8–6.0 qt) with filter | Drain plug ~40 Nm (30 lb-ft) |
| Coolant | Toyota Super Long Life Coolant (pink) | ~9–10 L (9.5–10.6 qt) | Bleed with heater on HOT |
| Automatic trans | Toyota ATF Type T-IV | Pan drop ~3.5–4.0 L (3.7–4.2 qt) | Pan bolts ~8–10 Nm; level at temp |
| Transfer case | Toyota ATF Type T-IV | ~1.1–1.5 L (1.2–1.6 qt) | Fill/drain ~39–49 Nm (29–36 lb-ft) |
| Front differential | 75W-90 GL-5 | ~1.4–1.6 L (1.5–1.7 qt) | Replace crush washers |
| Rear differential | 75W-90 GL-5 | ~3.0–3.2 L (3.2–3.4 qt) | Verify locker procedure if equipped |
| Brake fluid | DOT 3 | As required | Flush every 2 years |
| Power steering | Dexron III-type ATF | As required | Inspect hoses yearly |
| A/C refrigerant | R-134a | ~500–600 g (1.1–1.3 lb) | PAG oil per spec |
Performance and Economy
| Metric | 2003–2004 V6 4WD |
|---|---|
| 0–60 mph (0–100 km/h) | ~8.0–8.4 s |
| Top speed | ~112–115 mph (180–185 km/h) |
| Towing (braked) | Up to 5,000 lb (2,268 kg) |
| Payload | ~1,100–1,400 lb (500–635 kg) by trim |
| Roof load (dynamic) | ~100–150 lb (45–68 kg) |
| EPA-style economy (period) | ~17 mpg city / 21 mpg hwy (13.8 / 11.2 L/100 km) |
| Real highway @ 75 mph | ~18–20 mpg (13.1–11.8 L/100 km) |
Notes: Actual figures depend on axle code, tyre/wheel choice, options, and condition. Always confirm on-vehicle labels and official service data.
Trims and Options, Safety and Driver Assistance
Trims and key content (2003–2004, V6 4WD)
- SR5: Value-focused. Cloth seats, manual climate, 16-in wheels, roof rails, power windows/locks, stability/traction control, ABS/EBD, and often fog lamps. Common options include power driver seat, moonroof, and upgraded audio.
- Sport Edition: Adds a hood scoop, unique wheels, smoked accents, sport seats, and X-REAS cross-linked dampers that reduce pitch/roll during cornering and braking. Larger wheels/tyres are common.
- Limited: Leather, dual-zone automatic climate, JBL premium audio, heated seats, color-keyed cladding, and 17–18-in wheels. Many Limiteds include more sound insulation and convenience features such as HomeLink and optional navigation.
Mechanical/functional differences that affect ownership
- Suspension: X-REAS sharpens body control but is costlier to replace when it leaks. Many owners convert to high-quality conventional dampers; alignment is required after suspension work.
- Tyre packages: SR5’s 16-in package rides more softly and flexes better off-road; 17–18-in packages improve steering crispness at the expense of impact harshness.
- Driveline: All V6 4WD trucks use the multi-mode transfer case with a lockable center differential. Factory rear lockers are rare on these years; A-TRAC manages cross-axle slip effectively if you apply steady throttle.
Quick identifiers and build cues
- VIN engine code shows “1GR.” Sport’s hood scoop and graphite interior trim are obvious tells; Limited models have color-keyed flares/cladding and leather interiors. Look under the truck for X-REAS hydraulic lines running to the shocks to verify that option.
Safety ratings and equipment snapshot
- Passive: Dual-stage front airbags are standard; side torso and side-curtain airbags were available—confirm presence on the specific vehicle. Three-point belts at all seats; LATCH anchors for rear outboard positions.
- Active: ABS with EBD, Brake Assist, Vehicle Stability Control (VSC), and A-TRAC traction control. These predate modern radar/camera ADAS—no automatic emergency braking, adaptive cruise, or lane keeping to calibrate.
- Crash tests: The 4Runner tested well under early-2000s protocols, though direct comparisons to later, stricter test generations are not apples-to-apples. Always check VIN-based recall status for airbag modules and SRS harness-related campaigns.
Year-to-year notes
- 2003–2004: Launch configuration with the 4-speed automatic and the 245-hp rating. Equipment packaging differs slightly by trim and option bundle. In 2005 the V6 moved to a 5-speed and power ratings were revised under a new testing protocol.
Reliability, Common Issues and Service Actions
The early fourth-gen 4Runner is recognized for durability. Most age-related complaints trace to neglected fluids, corrosion in salt-belt climates, or wear items reaching end of life. Below are typical issues mapped by prevalence and cost.
Engine (1GR-FE)
- Water pump seep (common · medium):
Symptoms: Coolant crust at the weep hole, faint sweet smell, slow coolant loss.
Cause: Mechanical seal wear with age/miles.
Fix: Replace pump and thermostat; refill with SLLC; inspect belt and idlers. - Intake plenum gasket leaks (occasional · low):
Symptoms: Rough cold idle, lean fuel trims, P0171/P0174 codes.
Cause: Gasket hardening and shrinkage.
Fix: Replace upper plenum gaskets; clean MAF; verify PCV operation. - Secondary air injection faults (occasional · medium):
Symptoms: P041x–P244x codes, noisy pump on cold start.
Cause: Moisture intrusion or sticking switching valves on some trucks.
Fix: Replace pump/valves with updated parts; ensure drains and lines are clear. - Cooling plastics/hoses (common · low/medium):
Symptoms: Radiator end-tank seep, ballooned hoses.
Fix: Replace radiator/hoses; check fan clutch; bleed system thoroughly.
Transmission/Driveline (A340F, multi-mode 4WD)
- ATF degradation and light shudder (common · medium):
Symptoms: Harsh/late shifts, shudder at low speed.
Cause: Aged Type T-IV fluid and heat from towing or hills.
Fix: Drain/fill or gentle exchange with Type T-IV; set hot level precisely; consider an auxiliary cooler if towing frequently. - Transfer case “stiction” from disuse (common · low):
Symptoms: Hesitation or reluctance to engage 4H/4L/center-lock.
Cause: Rarely exercised actuators and clutches.
Fix: Monthly cycling on a loose surface through all modes; service fluid; address actuator faults if codes persist. - Differential seal weeps and bearing hum (occasional · low/medium):
Symptoms: Damp pinion seals; faint growl that changes with steering load.
Fix: Replace seals; set bearing preload correctly; use 75W-90 GL-5; rule out tyre noise first.
Suspension/Steering/Brakes
- X-REAS leaks (Sport/Limited) (occasional · medium/high):
Symptoms: Oily shocks, floaty diagonal motion, degraded damping.
Fix: Replace X-REAS components in matched pairs/sets or convert to conventional shocks; align after replacement. - Front wheel bearings (occasional · medium):
Symptoms: Speed-dependent growl, louder in gentle turns to one side.
Fix: Replace hub/bearing assembly; follow torque and preload specs. - Brake pulsation (common · low):
Cause: Uneven pad deposits/heat spots.
Fix: Quality rotors/pads, correct wheel lug torque (~113 Nm/83 lb-ft), and biennial brake fluid flushes.
Body/Electrical
- Frame/underbody rust (region-dependent · high severity):
Hotspots: Rear lower control arm mounts, crossmembers, brake/fuel lines, radiator support, and body seams.
Action: Lift and probe; treat scale early with converter and cavity wax; heavy perforation can be a walk-away or major repair. - Rear power window/regulator (occasional · low/medium):
Slow or stuck glass; replace regulator/motor; clean channels; confirm defogger wiring is intact. - Illumination bulbs and switches (occasional · low):
Straightforward repairs; expect a few as trucks age.
Recalls and service campaigns (verify by VIN)
- Airbag module/propellant-related campaigns may apply depending on build; some seatbelt anchor or SRS wiring checks appear in certain ranges. Always run a VIN lookup and ask for dealer records to confirm completion.
Pre-purchase checks to request
- Complete VIN recall check and service history printout.
- Underside inspection for frame corrosion, line rust, and crossmember integrity.
- Road-test 2H/4H (open and locked) and 4L on a loose surface; confirm smooth engagement with no warning lights.
- Transmission behavior under light throttle (shudder) and kickdown quality; budget an ATF service if unknown.
- Cooling system condition: water pump seep, radiator end-tank staining, hose integrity.
- X-REAS leaks on Sport/Limited; price a conversion or replacement into the deal.
- Wheel bearing noise and rear suspension bushing clunks over sharp bumps.
Maintenance and Buyer’s Guide
Practical maintenance schedule (distance/time, whichever comes first)
- Engine oil and filter: 5,000 mi (8,000 km) / 6 months; SAE 5W-30.
- Engine air filter: Inspect 15,000 mi (24,000 km); replace ~30,000 mi (48,000 km) or sooner in dust.
- Cabin filter: 15,000–20,000 mi (24,000–32,000 km) or annually.
- Spark plugs (iridium): 90,000–100,000 mi (145,000–160,000 km); torque ~18–21 Nm (13–15 lb-ft) on clean, dry threads.
- Coolant (SLLC): First at 100,000 mi (160,000 km) / 10 years; then every 5 years / 50,000 mi (80,000 km).
- Automatic transmission (Type T-IV): Inspect annually; service 60,000–90,000 mi (96,000–145,000 km), sooner if towing/hot climate. Set level at specified temperature.
- Transfer case (T-IV) and differentials (75W-90 GL-5): 30,000–50,000 mi (48,000–80,000 km) with towing/off-road use; up to 60,000 mi (96,000 km) in light duty.
- Brake fluid: DOT 3; flush every 2 years.
- Power steering fluid: Inspect yearly; refresh by 60,000–90,000 mi.
- Serpentine belt/idlers: Inspect each oil change; replace 60,000–90,000 mi.
- Tyre rotation and alignment check: 5,000–6,000 mi (8,000–10,000 km); maintain door-jamb pressures.
- Prop shafts/U-joints (if serviceable): Grease every 15,000–30,000 mi (24,000–48,000 km).
- 12 V battery: Load test annually after year 4; typical life 5–7 years.
- Valve gear: Shim-over-bucket; no routine adjustment—investigate only for noise, misfire, or correlation faults.
Fluid quick reference and capacities
- Engine oil: 5W-30 API SL/SN; ~6.0 qt with filter.
- ATF (A340F): Toyota ATF Type T-IV.
- Transfer case: Toyota ATF Type T-IV.
- Front/Rear diffs: 75W-90 GL-5 gear oil.
- Coolant: Toyota Super Long Life (pink) premix.
- Brake fluid: DOT 3 (DOT 4 acceptable after full flush).
- Power steering: Dexron III-type ATF.
Essential torque values (decision-critical)
- Wheel lug nuts: ~113 Nm (83 lb-ft)
- Engine oil drain plug: ~40 Nm (30 lb-ft)
- Diff/transfer fill & drain plugs: ~39–49 Nm (29–36 lb-ft)
- Front caliper bracket bolts: ~123 Nm (91 lb-ft)
- Rear lower control arm to frame: ~160–180 Nm (118–133 lb-ft) (verify by axle code)
Buyer’s checklist: what to look for
- Prefer: Dry-climate frames, full driveline-fluid history (ATF/transfer/diffs), recent cooling system service, documented timing-chain quiet operation (no rattle on cold start), and evidence of monthly 4WD cycling.
- Be cautious with: Extensive frame rust near control-arm mounts or crossmembers, sustained transmission shudder, leaking X-REAS, persistent ABS/VSC lights tied to wheel-speed or yaw sensors, and lifted trucks lacking caster/camber printouts.
- Budgeting guide: Complete fluid baseline $300–600 DIY ($700–1,100 shop), quality tyres $700–1,200, front wheel bearings $450–900, shock/strut refresh $500–1,800 (X-REAS vs conventional).
Durability outlook
With routine fluids, rust prevention, and prompt attention to early warning signs (coolant weeps, bearing noise), the 1GR-FE/A340F combination and 120-series frame commonly deliver 200,000–300,000 miles (320,000–480,000 km) of reliable service.
Driving and Performance
Ride, handling, and NVH
The independent front suspension and long wheelbase make the 4Runner stable at speed and composed over broken pavement. Steering is moderate in weight with a steady on-center feel. Body roll remains present—this is a tall, ladder-frame SUV—but it’s well controlled with healthy dampers, and X-REAS further curbs pitch/roll for drivers who value flatter response. Road and tyre noise are modest; wind buffeting mostly appears around the A-pillars at highway speeds.
Powertrain character
The 1GR-FE’s low-rpm torque and responsive throttle make it feel eager in traffic and confident on grades. The A340F’s four ratios are widely spaced; the drop between gears is noticeable compared with later 5-speed models, but kickdowns are decisive and overdrive keeps cruise revs calm. The combination suits towing up to the rated limit when you respect tongue weight and use a weight-distributing hitch.
Real-world economy
Expect ~17–19 mpg (13.8–12.4 L/100 km) in mixed use. At a steady 75 mph (120 km/h), 18–20 mpg (13.1–11.8 L/100 km) is realistic with stock ride height and highway tyres. Roof baskets, aggressive A/T tyres, winter fuel, and lifts can reduce economy by 1–3 mpg. Running 2H on dry pavement and keeping tyres at door-jamb pressures helps.
Key metrics (relevant to buyers)
- 0–60 mph: ~8.0–8.4 s in stock form.
- 50–80 mph passing: Strong in 3rd; downshift logic is predictable.
- Braking feel: Linear with decent heat tolerance; fresh fluid and quality pads maintain pedal consistency on long descents.
- Turning circle: ~36–37 ft; easy to maneuver in urban parking.
Traction and control
On mixed-grip surfaces (patchy snow, wet gravel), 4H with the center differential open preserves smoothness and avoids wind-up. When conditions are uniformly slick, lock the center diff for a fixed 50:50 split. Use 4L for technical terrain or steep, slow sections. A-TRAC works best with steady throttle—allow the system to pulse the brakes and transfer torque. Tyre selection remains the biggest determinant of off-pavement success; quality all-terrains transform capability and sidewall robustness.
Towing and load behavior
Within the 5,000-lb (2,268-kg) rating, the 4Runner tows confidently if the suspension is fresh, tongue weight is ~10–12%, and the hitch setup is correct. Anticipate a 15–30% fuel-economy penalty at 60–65 mph (97–105 km/h); more at higher speeds or in headwinds. For frequent towing in hot climates or mountains, an auxiliary trans cooler is inexpensive protection.
How 4Runner Compares to Rivals
Honda Pilot (first gen)
Smoother unibody ride, lower fuel use, and family-friendly packaging with an easy third row. But it lacks low range and isn’t designed for repeated heat loads while towing on grades. For snow-day commuting, the Pilot is fine; for towing and trail networks, the 4Runner’s ladder frame and transfer case win.
Ford Explorer (early-2000s)
Explorer keeps a frame and offers V8 torque. Purchase prices can be lower, but lifetime repair frequency and parts durability generally favor the Toyota. The 4Runner’s multi-mode 4WD and timing-chain V6 reduce maintenance complexity.
Nissan Pathfinder (R50/R51 transition era)
Comparable size with genuine low range on many trims. The 4Runner counters with a calmer highway ride and interior that ages gracefully. Corrosion vigilance applies to both, particularly in salt-belt vehicles.
Jeep Grand Cherokee (WJ)
Jeep offers sophisticated 4×4 systems and V8 options with strong low-speed control. The 4Runner focuses on simplicity, reliability, and long-term running costs. Choose Jeep for maximal off-road articulation and gadgets; choose 4Runner for a broader mix of highway comfort, towing, and fewer shop visits.
Bottom line
If you need true 4WD with low range, a stout frame, and a reputation for going the distance, the 2003–2004 4Runner V6 4WD remains one of the most balanced choices. Crossovers ride softer and sip less fuel, but few match this Toyota’s mix of durability, versatility, and ease of ownership.
References
- 2003 Toyota 4Runner Owner’s Manual 2003 (Owner’s Manual)
- 2004 Toyota 4Runner Owner’s Manual 2004 (Owner’s Manual)
- Fuel Economy of 2004 Toyota 4Runner 2004 (Official Ratings)
- Toyota 4Runner 4-door SUV (2004) Ratings 2004 (Safety Rating)
- NHTSA Recalls 2003–2004 (Recall Database)
Disclaimer
This article is for informational purposes only and is not a substitute for professional diagnosis or repair. Specifications, torque values, intervals, and procedures vary by VIN, market, and equipment; always verify against official service documentation and on-vehicle labels. If you found this helpful, please consider sharing it on Facebook or X/Twitter to support xcar’s work.