Luxury Mid-size SUV, often cross-shopped with Lexus RX, Acura MDX, and BMW X5 of the era.
Competitive Analysis
Differentiation:
Offered a comfortable, refined ride with a standard V6 engine and available 4WD, leveraging Nissan's proven truck and SUV platform (shared with Pathfinder).
Key Features
Engine Powertrain:
3.5L VQ35DE V6 engine and available ATTESA E-TS All-Mode 4WD system provided capable performance.
Luxury Appointments:
Premium interior materials, leather seating, Bose audio system, and available navigation were hallmarks of its luxury positioning.
Airbag system (SRS), seat belt pre-tensioners, occupant classification system, diagnostic procedures for SRS.
HVAC:
Air conditioning system (compressor, condenser, evaporator, refrigerant), heater core, blower motor, climate control unit, diagnostic procedures, refrigerant charging specifications.
Step-by-step troubleshooting flowcharts for common and uncommon issues, symptom-based diagnostics, DTC (Diagnostic Trouble Code) interpretation.
Repair Overhaul:
Complete disassembly and reassembly procedures for all major components and systems, torque specifications for critical fasteners, special tool requirements.
Electrical Diagnostics:
Detailed wiring diagrams, component testing procedures, voltage and resistance checks, signal tracing.
Special Tools:
Identification and use of specialized tools required for specific repairs (e.g., press tools, alignment equipment, diagnostic scanners).
Technical Depth
Depth:
Comprehensive (from basic maintenance to complete engine and transmission rebuilds, including complex electrical diagnostics).
Detail Level:
Factory-level detail with substeps, notes, cautions, and warnings for critical procedures.
📊 Manual Specifications
File Format
Quality:
High-resolution PDF, searchable text, vector graphics for diagrams.
Print Quality
Printability:
Fully printable on standard printers, with options for individual page printing or sections.
Binding Type
Binding:
N/A (Digital Download - No physical binding)
Paper Type
Paper Type:
N/A (Digital Download - No physical paper)
Software Requirements
Reader Requirement:
Adobe Acrobat Reader (or compatible PDF viewer)
Compression Requirement:
WinZip (or compatible file archiver for initial download)
⚙️ Engine Specifications
Primary Engine
Engine Code:
VQ35DE
Engine Type:
3.5L (3498cc) DOHC 24-valve V6
Bore X Stroke:
95.5 mm x 81.4 mm
Compression Ratio:
9.7:1
Performance
Horsepower:
240 hp @ 6000 rpm (approx.)
Torque:
265 lb-ft @ 3200 rpm (approx.)
Fuel System
Fuel Delivery:
Electronic Fuel Injection (EFI)
Fuel Type:
Unleaded gasoline, 87 octane recommended
Lubrication
Oil Capacity:
4.8 US quarts (4.5 liters) with filter change (VQ35DE)
Oil Specification:
API SG or higher, SAE 5W-30 or 10W-30 viscosity (refer to manual for exact seasonal recommendations)
🔧 Transmission
Standard
Type:
4-speed Automatic (RE4R01A)
Optional
Type:
5-speed Manual (RM01A)
Features
4Wd System:
ATTESA E-TS (All-Mode Four-Wheel Drive) with electronic torque split control
Fluid Specification
Automatic Transmission Fluid:
Nissan Matic Fluid J or equivalent DEXRON III/MERCON
Manual Transmission Fluid:
API GL-4 or GL-5, SAE 75W-85 or 75W-90 viscosity
📐 Dimensions
Exterior
Wheelbase:
111.2 inches (2824 mm)
Length:
189.1 inches (4803 mm)
Width:
71.7 inches (1821 mm)
Height:
65.7 inches (1669 mm)
Weights
Curb Weight:
4100 - 4300 lbs (approx., depending on drivetrain and options)
Cargo
Cargo Volume:
37.1 cu ft (behind rear seats), 79.8 cu ft (with rear seats folded)
🛡️ Safety Features
Ratings
NHTSA Frontal Crash:
5-Star Driver and Passenger (for relevant model years, check specific year ratings)
IIHS Side Impact:
'Acceptable' or 'Good' depending on year and specific test configurations (check IIHS archives).
Active Features
ABS:
Standard Anti-lock Braking System
Traction Control:
Available Traction Control System (TCS) on some models.
Passive Features
Airbags:
Front dual-stage airbags, available front side-impact airbags.
Seat Belts:
3-point front and rear seat belts, front seat belt pre-tensioners.
💡 Technology Features
Infotainment
Audio System:
Available Bose premium audio system with CD player and AM/FM radio.
Navigation:
Optional factory DVD-based navigation system.
Driver Assistance
Cruise Control:
Standard cruise control.
Connectivity
Multiplex Communication:
Utilizes a multiplex wiring system (akin to early CAN bus) for various control modules, detailed in the electrical section.
🔧 Maintenance
Service Intervals
Oil Change Interval:
Every 3,750 miles or 3 months for severe service, 7,500 miles or 6 months for normal service (refer to owner's manual for specific recommendations and oil type).
Engine Air Filter:
Inspect every 15,000 miles, replace as needed. Replace every 30,000 miles or sooner if dirty.
Spark Plugs:
Platinum-tipped plugs typically have a 100,000-mile replacement interval. Iridium plugs could have a longer interval. Consult manual for exact type and interval.
Transmission Fluid Change:
Every 30,000-60,000 miles, depending on driving conditions (severe vs. normal service). Check manual for specific recommendations.
Coolant Change:
Initial change at 30,000 miles or 2 years, then every 30,000 miles or 2 years thereafter. Use Nissan Genuine Super Long Life Coolant (Blue).
Fluid Specifications
Brake Fluid:
DOT 3
Power Steering Fluid:
Nissan Genuine Power Steering Fluid or equivalent DEXRON II/III ATF.
Differential Fluid:
API GL-5, SAE 80W-90 gear oil for both front and rear differentials.
Known Issues
Intake Manifold Gasket Leaks:
Common on the VQ35DE engine, can cause coolant or vacuum leaks.
Transfer Case Actuator Failure:
The electronic actuator for the ATTESA E-TS system can fail, leading to 4WD system faults.
Oil Cooler Hose Leaks:
O-rings and hoses for the engine oil cooler can degrade and leak.
Cv Joint Boots:
Ruptured CV joint boots can lead to premature wear and failure of the joints.
Window Regulator Failure:
Power window regulators can wear out and fail.
📚 Vehicle History
Brand Heritage
Infiniti Launch:
Infiniti was launched by Nissan in 1989 as a luxury brand in North America.
Model Evolution
Qx4 Introduction:
The QX4 was introduced for the 1997 model year, based on the second-generation Nissan Pathfinder (R50).
Model Updates 01-03:
The 2001 model year brought significant updates, including the new 3.5L VQ35DE engine and styling revisions. Later models in this range (2002-2003) saw minor equipment shuffling and refinements.
Production
Manufacturing Location:
Japan (primarily)
🏆 Awards & Recognition
Recognitions
Jd Power Initial Quality:
Infiniti models frequently ranked well in J.D. Power Initial Quality studies during this period, reflecting Nissan's quality improvements.
Ward Auto Engines:
The VQ35DE engine was a consistent recipient of Ward's 10 Best Engines awards.