The 1999–2002 Toyota 4Runner 4WD with the 5VZ-FE 3.4-liter V6 (chassis family VZN185) is the facelifted phase of Toyota’s third-generation mid-size SUV. It blends a stout ladder frame and part-time four-wheel drive with the refinement of Toyota’s torque-rich V6 and a roomy five-passenger cabin. This article focuses specifically on the 4WD V6 configuration offered during these years, available with a 4-speed automatic or, more rarely, a 5-speed manual. Buyers choose it for its long-term durability, true low-range capability, and broad parts support, while accepting truck-like NVH and fuel economy typical of the era. Below you will find a deep look at what matters most to owners and shoppers: how it is built, exact specifications and fluid data, real-world driving and economy, known issues and remedies, practical maintenance schedules with torque values, plus a concise buyer’s checklist and rival comparison to help you make a confident decision.
At a Glance
- Proven 5VZ-FE V6 with a predictable timing belt service and strong midrange torque for towing and grades.
- Robust part-time 4WD with low range; optional factory rear differential lock enables confident, low-speed traction.
- Hydraulic rack-and-pinion steering and coil-spring rear suspension deliver stable highway manners for a body-on-frame SUV.
- Caveat: watch for radiator ATF-cooler failures on automatics; a fresh radiator or external cooler is smart prevention.
- Typical interval: Timing belt + water pump every 90,000 mi (145,000 km) or 6–7 years; brake fluid every 2 years.
Navigate this guide
- Detailed Overview — 4Runner V6 4WD
- Specifications and Technical Data — VZN185 5VZ-FE
- 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 — 4Runner V6 4WD
The facelifted third-gen 4Runner refined Toyota’s durable truck architecture without losing the mechanical honesty enthusiasts value. Underneath sits a boxed ladder frame designed for longevity and easy service access. Front suspension is double-wishbone with coilover struts; the rear is a four-link, coil-sprung solid axle. The combination delivers better on-road stability than leaf-spring rivals and keeps articulation friendly for mild to moderate trails. Steering is hydraulic rack-and-pinion, which helps these trucks track straight at highway speeds and makes on-center feel more precise than many period SUVs.
Power comes from the 5VZ-FE 3.4-liter V6: iron block, aluminum heads, dual overhead cams, 24 valves, and a timing belt (non-interference). The engine’s character is all about accessible torque and smoothness from low revs to about 4,800 rpm where it delivers its rated 183 hp (135 kW). With proper care, it is known to exceed 300,000 miles (480,000 km) on the original long block. Intake serviceability is good: the hot-wire MAF and idle-air control (IAC) are easy to clean when age brings rough idle. Most 4WD trucks are paired to the A340F 4-speed automatic; a 5-speed manual (R150F) exists in small numbers and is prized by off-roaders for control and simplicity.
The part-time 4WD system is straightforward: 2H for dry pavement, 4H for loose or slippery surfaces, and 4L (low range) for steep or technical terrain. Many trucks use an Automatic Disconnecting Differential (ADD) up front with vacuum actuators; hoses and solenoids should be inspected on older examples. A factory electronic rear differential lock was available on select builds—highly desirable for owners who regularly tackle snow, mud, or rocky climbs. Brakes are front ventilated discs and rear drums; while modest by modern standards, fresh fluid, correct rear drum adjustment, and lubricated slide pins restore strong, repeatable stops.
Inside, the cabin seats five, with Toyota’s classic roll-down tailgate glass that improves airflow and allows long cargo to pass through. SR5 models are the enthusiast sweet spot for capability and value, while Limited trims skew to leather and more sound insulation. Compared with the 2WD V6, the 4WD adds weight and driveline losses but returns genuine capability and trail durability. Compared with the four-cylinder 4WD, the V6 is quieter, more effortless on grades, and better suited to towing—without adding complexity beyond the belt service.
Specifications and Technical Data — VZN185 5VZ-FE
Engine and Performance (gasoline, naturally aspirated)
| Item | Value |
|---|---|
| Code & layout | 5VZ-FE V6, DOHC, 24-valve, timing belt |
| Displacement | 3.4 L (3,378 cc) |
| Compression ratio | ~9.6:1 |
| Induction & fueling | Naturally aspirated; multi-point EFI; hot-wire MAF |
| Rated power | 183 hp (135 kW) @ ~4,800 rpm |
| Rated torque | 295 Nm (217 lb-ft) @ ~3,600–3,800 rpm |
| Emissions/diagnostics | OBD-II |
| Fuel requirement | Regular unleaded |
| Fuel tank (usable) | ~70 L (18.5 gal) |
| Highway at 120 km/h (75 mph) | Often near EPA combined when stock; racks/lifts/AT tires reduce economy 5–20% |
| Aerodynamics (context) | Cd mid-0.4s; frontal area ~2.7–2.8 m² |
Transmission and Driveline (4×4)
| Item | Value |
|---|---|
| Transmissions | 4-speed automatic (A340F); 5-speed manual (R150F) rare |
| Transfer case | Part-time 4WD; 2H / 4H / 4L; low-range ~2.57:1 |
| Front axle engagement | ADD vacuum actuator on many builds; inspect lines/solenoids |
| Rear differential | Open; factory electronic locker available on select trucks |
| Final drive ratios (typical) | ~4.10–4.30 (varies by build/locker option) |
| Refuel to full | ~70 L / 18.5 gal (typical pump time ~2–3 min) |
Chassis and Dimensions
| Item | Value |
|---|---|
| Frame | Boxed ladder frame |
| Front suspension | Double-wishbone with coilover; stabilizer bar |
| Rear suspension | Four-link solid axle with coils; stabilizer bar |
| Steering | Hydraulic rack-and-pinion |
| Brakes | Front ventilated discs; rear drums; ABS availability by trim |
| Wheels/tires (factory) | 15–16 in; common sizes 225/75R15 to 265/70R16 |
| Wheelbase | 2,675 mm (105.3 in) |
| Length | ≈ 4,653–4,656 mm (183.2–183.3 in) |
| Width (body) | ≈ 1,690–1,730 mm (66.5–68.1 in) |
| Height | ≈ 1,715–1,740 mm (67.5–68.5 in) |
| Ground clearance | ≈ 230–240 mm (9.1–9.4 in) stock |
| Curb weight (4WD V6) | ≈ 1,780–1,920 kg (3,925–4,230 lb) |
| GVWR | ≈ 2,380–2,495 kg (5,250–5,500 lb) |
| Turning circle | ≈ 11.6–11.9 m (38–39 ft) |
| Cargo volume (up/down) | ≈ 1,260 L / 2,260 L (≈45 / 80 cu ft) |
Fluids and Capacities (service planning)
| System | Specification & Capacity (typical) |
|---|---|
| Engine oil | 5W-30, ~5.2–5.7 L (5.5–6.0 qt) with filter |
| Coolant | Toyota Long-Life (red) / Super Long Life (pink), total ~9–10 L |
| Automatic transmission (A340F) | Toyota Type T-IV / Dexron III, drain/fill ~2.5–3.5 L; dry ~8–9 L |
| Manual transmission (R150F) | 75W-90 GL-4/GL-5, ~2.3–2.6 L |
| Transfer case | 75W-90 GL-4/GL-5, ~1.2–1.5 L |
| Front differential | 75W-90 GL-5, ~1.1–1.3 L |
| Rear differential | 75W-90 GL-5, ~2.5–3.0 L (locker may require friction modifier per label) |
| Brake fluid | DOT 3/4; flush every 2 years |
| Power steering | ATF Dexron II/III (per reservoir cap) |
Selected torque values (frequently used):
- Wheel lug nuts — 113 Nm (83 lb-ft)
- Front caliper brackets — ~122 Nm (90 lb-ft)
- Differential drain/fill — ~49–59 Nm (36–44 lb-ft)
- Engine oil drain plug — ~39 Nm (29 lb-ft)
- Spark plugs — 18–22 Nm (13–16 lb-ft) (aluminum heads; follow plug maker guidance)
Performance and Economy (4×4 V6)
| Metric | 4-AT (A340F) | 5-MT (R150F, rare) |
|---|---|---|
| 0–60 mph (typical ranges) | ~9.8–10.8 s | ~9.4–10.2 s |
| Top speed (indicated) | ~105–110 mph | ~110 mph |
| EPA mpg (city/hwy/comb) | 15 / 18 / 16 | 15 / 18 / 16 (similar gearing) |
| Comb L/100 km (approx.) | ~14.7 | ~14.7 |
| Tow rating (braked)* | Up to 2,268 kg (5,000 lb) when properly equipped | |
| Payload (typical) | ~400–550 kg (880–1,210 lb) | |
| Roof load (dynamic) | ~75–100 kg (165–220 lb), rack dependent |
*For mountain grades or hot climates, an auxiliary ATF cooler is inexpensive insurance on automatics.
Trims and Options, Safety and Driver Assistance
Trim overview (1999–2002, 4WD V6 emphasis):
- Base: Cloth seats, manual HVAC, steel wheels (often 15-inch), part-time 4WD with low range. ABS presence varies by build.
- SR5: The most common and best balanced. Adds alloy wheels, power accessories, roof rack, upgraded upholstery, and—on certain packages—16-inch wheels with larger front rotors.
- Limited: Leather, premium audio, color-keyed cladding, and extra sound insulation. Many Limiteds pair with automatic transmissions; verify wheel/rotor sizes for correct parts ordering.
Key option packages and mechanical tells:
- Factory electronic rear differential lock: Look for the dash switch near the steering wheel and confirm axle code on the door jamb sticker.
- Axle ratios: Codes indicate gearing (e.g., 4.10 vs 4.30). Numerically higher ratios help towing and larger-than-stock tires.
- Tow package: Auxiliary ATF cooler and higher-capacity alternator on many builds.
- ABS specifics: Proper bleed sequences matter; neglected fluid often explains a soft pedal.
Safety ratings (period context):
- In era-appropriate testing, the third-gen 4Runner earned Acceptable in the IIHS moderate-overlap frontal evaluation for these years. NHTSA protocols of the time flagged tall, body-on-frame SUVs for rollover risk relative to modern crossovers; driving within the truck’s limits and running fresh, grippy tires remain critical.
Safety systems and child-seat provisions:
- Dual front airbags and pretensioners were standard by the facelift. These trucks predate LATCH; install child seats using seat belts and approved locking methods per the owner’s manual. Advanced driver aids (AEB, lane assist, adaptive cruise) were not offered—maintenance and tire quality carry the safety load.
Year-to-year notes (1999–2002):
- The 1999 facelift updated exterior and interior details; later years saw incremental trim and NVH improvements. Core mechanicals stayed consistent: same engine family, transmissions, and 4WD hardware.
Reliability, Common Issues and Service Actions
Reliability snapshot: The VZN185 4WD with 5VZ-FE is among the most durable mid-size SUVs of its era. Today’s problems skew toward age, climate, and modifications rather than inherent design flaws. Use this prevalence/cost map to plan inspections and budgets.
Common (frequent; low-to-medium cost)
- Timing belt & water pump overdue:
Symptoms: unknown belt age; coolant seep at pump; chirps from idlers.
Root cause: elapsed time/mileage.
Remedy: full belt kit (belt, pump, idlers, tensioner), thermostat, and front seals as needed; reset the service clock. - Radiator ATF-cooler failure (“pink milkshake” on automatics):
Symptoms: strawberry-colored fluid, harsh shifts, cross-contamination.
Remedy: replace radiator proactively; flush ATF thoroughly; consider a quality external cooler bypass. - MAF/IAC contamination & vacuum leaks:
Symptoms: unstable idle, P0171 lean codes, hesitation.
Remedy: clean MAF/IAC with correct sprays; smoke test intake; replace brittle hoses. - Valve cover and half-moon plug leaks:
Symptoms: oil film on heads, odor near exhaust, oil in plug tubes.
Remedy: new gaskets/seals; verify PCV function; torque to spec. - Rear axle seals wetting brake shoes:
Symptoms: oil on backing plates; weak parking brake.
Remedy: replace seals (and bearings if noisy); clean/renew shoes and hardware; ensure axle breather moves freely.
Occasional (medium prevalence; medium cost)
- Lower ball joints (LBJs) and inner/outer tie-rods:
Symptoms: wander, clunks, toe change over bumps.
Remedy: replace with quality parts; torque at ride height; align afterward. - A340F shift-feel degradation when hot:
Symptoms: 2–3 flare, lazy lock-up.
Remedy: staged drain/fills with T-IV/Dex III (as labeled); check throttle/kickdown cable (if equipped); valve-body service if persistent. - 4WD ADD vacuum system faults:
Symptoms: 4H light flashes; delayed or no engagement.
Remedy: test solenoids; replace cracked vacuum lines; verify front-axle actuator travel.
Rare (low prevalence; high impact)
- Head gasket failure: Uncommon on well-maintained engines; most cases follow severe overheating.
- ABS modulator leaks/failures: Expensive; diagnose carefully before parts replacement.
- Transfer-case chain stretch (very high mileage/abuse): Presents as metallic whir or jump in 4H/4L under load—replace chain and inspect sprockets.
Corrosion hotspots (salt-belt emphasis)
- Rear frame kick-ups, body mounts, fuel-tank straps, and inner boxed sections; borescope inspections are strongly recommended. Treat and coat early; welded repairs where advanced.
Recalls and service actions
- Campaigns vary by VIN; there is no single universal powertrain recall unique to this 4WD V6 subset. Always run an official VIN recall check and keep dealer records of completion for resale and safety assurance.
Pre-purchase documents to request
- Timing belt service invoice (with parts list), cooling-system replacements, ATF drain/fill history and any auxiliary cooler, front-end rebuild work (LBJs, tie-rods, bushings), and brake-fluid flush intervals. Frame inspection photos are a plus.
Maintenance and Buyer’s Guide
Practical maintenance schedule (normal service; tighten for towing, short-trip, dust, or extreme temps):
- Engine oil & filter: 5,000 mi (8,000 km) or 6 months, 5W-30.
- Timing belt kit + water pump: 90,000 mi (145,000 km) or 6–7 years; include idlers/tensioner, thermostat, and inspect front seals.
- Engine air filter: Inspect 12 months / 15,000 mi (24,000 km); replace on condition.
- Cabin filtration: Many trucks lacked a factory cabin filter; retrofit is easy—inspect HVAC box annually.
- Spark plugs: 30,000–60,000 mi (48,000–96,000 km) depending on plug type; verify gap/torque.
- Fuel filter (external): 60,000–90,000 mi (96,000–145,000 km); inspect lines for corrosion.
- Coolant: Red Long-Life 2–3 years / 30,000–50,000 mi; Pink SLLC 5–7 years / 100,000–150,000 mi—do not mix types.
- Drive belts & hoses: Inspect each oil change; replace 60,000–90,000 mi or as needed.
- A340F ATF (automatic): Drain/fill 30,000–60,000 mi; avoid power flushes on high-milers—use staged services; add/maintain external cooler if towing.
- Manual gearbox (R150F), transfer case, diffs: 30,000–60,000 mi depending on use/water crossings; confirm breathers are free.
- Brake fluid: Flush every 2 years; service front slide pins; adjust rear drums.
- Pads/shoes/rotors/drums: Inspect at each rotation; replace to spec; renew drum hardware if weak return springs or uneven wear.
- Tire rotation & alignment: Rotate 5,000–7,500 mi; align annually or after front-end work.
- Valve lash: Hydraulic on 5VZ-FE—no routine checks unless symptoms arise.
- 12 V battery: Load-test annually after year 3; typical life 4–6 years.
Fluid quick sheet & capacities (recap):
- Engine oil: 5W-30; ~5.5–6.0 qt with filter.
- A340F automatic: Type T-IV/Dex III; drain/fill ~2.5–3.5 L (dry ~8–9 L).
- Manual/transfer/diffs: 75W-90 GL-4/GL-5; see capacities above.
- Coolant: 9–10 L Toyota LL/SLLC.
- Brake fluid: DOT 3/4; every 2 years.
Essential torque values:
- Lug nuts 113 Nm (83 lb-ft); oil drain ~39 Nm (29 lb-ft); diff plugs ~49–59 Nm (36–44 lb-ft); spark plugs 18–22 Nm (13–16 lb-ft).
Buyer’s inspection checklist (4×4 emphasis):
- Frame & rails: Probe rear kick-ups, body mounts, tank straps; borescope inside boxed sections for hidden perforation; beware fresh undercoat over heavy scale.
- 4WD system: On loose surface, confirm 4H/4L engagement; watch the indicator; listen for actuator movement; inspect ADD vacuum lines/solenoids.
- Transmission:
- Automatic: From hot, look for clean 1–2/2–3 shifts and steady lock-up; no flare/shudder; ask for ATF service proof and any cooler install.
- Manual: Smooth engagement, no synchro crunch, and no driveline lash when on-off throttle.
- Cooling system: Check radiator end-tanks, evidence of ATF/coolant mixing, thermostat housing seep, heater performance.
- Front end: LBJs, tie-rods, control-arm bushings, and front wheel bearings; alignments should hold and on-center feel should be calm.
- Brakes: Straight stops, no pulsation; confirm rear drum adjustment; inspect caliper slide pins for free motion.
- Electrical: Rear window works; alternator output under load; grounds clean/tight.
- Body/seals: Windshield surround, roof rack mounts, tailgate trim, door drains; look for leak tracks behind quarter-panel trim.
- Wheels/tires: Oversized mud-terrains on stock gearing sap performance and stress LBJs/brakes; intelligent AT choices strike a better balance.
What to seek/avoid:
- Seek: Stock or lightly modified SR5 4WD with documented timing belt and cooling service, clean frame, functional 4WD, and recent brake/ATF maintenance. A factory rear locker is a plus for snow and trails.
- Be cautious of: ATF “milkshake” survivors without full remediation, heavy lifts on 33s without re-gearing, undercoating hiding frame repairs, and long-overdue belt histories.
- Durability outlook: With corrosion managed and fluids on time, these trucks routinely reach 300,000+ miles (480,000+ km) with original long blocks and undisturbed transfer cases.
Driving and Performance
Ride and handling: For a ladder-frame SUV, the 4Runner rides impressively well. Coil springs at both ends, healthy shocks, and intact bushings keep secondary motions under control. Steering is moderate-weight with predictable on-center; if the truck wanders, suspect LBJs, toe-out, or tired bushings before blaming the design. Stabilizer bars limit roll without making the ride brittle.
Powertrain character: The 5VZ-FE’s strength is midrange pull. Around town, it moves off smoothly with little throttle; on grades or when towing, it is happiest between 3,000 and 4,800 rpm. The A340F shifts smoothly and decisively when fluid is fresh; when hot and neglected, it can flare on the 2–3 shift. The R150F manual pairs beautifully with low range for precise crawling and engine-braking on descents, trading convenience for control.
Braking: Disc-drum hardware requires correct setup to shine. Fresh DOT 3/4, bled properly, and rear drums adjusted, transform pedal consistency. Higher-friction pads and stainless lines can improve modulation for mountain driving; ultimate stopping still depends on tire grip.
Real-world efficiency: Stock 4WD V6 trucks typically return 15–18 mpg (US) mixed (13–16 L/100 km). At 75 mph (120 km/h), many owners hover near EPA combined. Roof racks, lifts, and aggressive all-terrains extract a 5–20% penalty. Cold weather and short trips nudge consumption further.
Traction and control: The part-time system is simple and durable. Use 2H on dry pavement to avoid driveline wind-up, 4H for rain, snow, gravel, or sand, and 4L for steep climbs, descents, or slow technical work. Trucks equipped with the rear locker claw forward where open-diff trucks spin. Tire selection and pressure are the biggest levers for off-road performance; a mild lift, skid plates, and proper recovery points are reliability-friendly upgrades that preserve on-road manners.
Load and towing: Properly equipped, tow up to 5,000 lb (2,268 kg). For comfort, braking margin, and temperature control, most owners are happiest 1,500–3,500 lb (680–1,590 kg) with trailer brakes. Expect a 25–40% fuel-economy hit under sustained towing or full loads, especially in headwinds or on long grades; monitor trans temps and consider a stacked-plate cooler on automatics.
How 4Runner Compares to Rivals
Jeep Grand Cherokee WJ 4×4 (4.0L/4.7L): Quicker in V8 form and comfortable on road, but electrical gremlins and cooling quirks surface on high-milers. The 4Runner trades outright speed for a simpler ownership pattern, excellent parts support, and higher long-term reliability.
Nissan Pathfinder R50 4×4 (3.3L V6): Unibody construction yields a slightly more car-like ride; timing belt service cadence is similar to the 5VZ-FE. The 4Runner’s aftermarket ecosystem is broader, and its ladder frame better suits sustained towing and rough roads.
Ford Explorer 4×4 (’99–’01, OHV/SOHC V6): Plentiful and inexpensive, but the SOHC timing chain layout is more complex and failure-prone with age. Steering feel and front-end durability age better on the Toyota, and resale is stronger.
Chevrolet Blazer 4×4 (S-series): Compact and affordable. Torsion-bar front ends and aging 4×4 hardware may need steady attention. The 4Runner’s V6 is smoother, its cabin materials last longer, and frame corrosion tends to be less catastrophic when managed.
Bottom line: If you want longevity, real 4×4 hardware with low range, and predictable maintenance, the VZN185 5VZ-FE sits near the top of the class. If you prioritize quicker highway passing or heavy towing every weekend, a newer platform or a V8 alternative may better suit your use case.
References
- Gas Mileage of 1999 Toyota 4Runner 2025 (EPA/DOE Database)
- 1999 Toyota 4Runner 2025 (Safety Rating)
- Scheduled Maintenance Guide 1999 (Owner’s Manual Supplement)
- Look up Safety Recalls & Service Campaigns by VIN 2025 (Recall Database)
Disclaimer
This article is for informational purposes and is not a substitute for professional diagnosis or repair. Specifications, torque values, intervals, and procedures can vary by VIN, market, options, and build date. Always verify against your official Toyota service documentation and under-hood labels. If this guide helped, please consider sharing it with fellow enthusiasts on Facebook or X/Twitter to support xcar’s work.