Infiniti QX70 (FX): History and Generations

The Infiniti FX/QX70 was produced in two main generations, both built on Nissan’s sporty rear-wheel-drive FM platform, shared with the Nissan 370Z.

First Generation (Infiniti FX S50, 2003–2008):
Debuting in 2003, this generation was available as the FX35 (V6 VQ35DE) and FX45 (V8 VK45DE). It quickly became popular for its bold design and sporty performance, offering drivers a unique crossover experience that blended speed, agility, and comfort.

Second Generation (Infiniti FX S51, 2008–2017):
Introduced in 2008, this generation retained the recognizable silhouette but featured a refreshed design, upgraded interior, and new engines. In 2013, Infiniti renamed the FX to QX70 as part of its new model-naming strategy.

• FX35/FX37/QX70 3.7: Equipped with V6 engines (VQ35HR for FX35, VQ37VHR for FX37/QX70 3.7).

• FX50/QX70 5.0: Top-of-the-line model with a powerful V8 engine (VK50VE).

• FX30d/QX70 3.0d: Diesel variant for the European market, using a V6 V9X engine.

Engines and Transmissions

The engine lineup is a major strength of the QX70/FX, but it can also be a source of potential issues.

Gasoline Engines:

• 3.5L V6 (VQ35DE/VQ35HR, 280–307 hp): Used in FX35. Generally reliable, but high-mileage examples (over 200,000 km) may experience oil consumption, valve cover gasket leaks, and throttle body deposits.

• 3.7L V6 (VQ37VHR, 333 hp): Found in FX37/QX70 3.7. Considered an evolution of the VQ35 with fewer common issues.

• 4.5L V8 (VK45DE, 320 hp): Used in FX45. Reliable but requires careful maintenance.

• 5.0L V8 (VK50VE, 390–420 hp): Found in FX50/QX70 5.0. High-performance V8 with potential cylinder scoring issues, higher oil consumption, and cooling system sensitivity.

Diesel Engine:

• 3.0L V6 (V9X, 238–240 hp): FX30d/QX70 3.0d. Economical and dynamic but limited lifespan (~300,000 km before major overhaul). Common issues include piston ring sticking, crankshaft bearing wear, timing chain wear (after 100–150k km), and EGR valve clogging.

Transmissions:

• 5-speed automatic (1st generation): Reliable but requires regular oil changes.

• 7-speed automatic (2nd generation): Standard on all 2nd-gen models, durable and smooth. Sensitive to overheating; aggressive driving or delayed maintenance can cause shifts issues. Additional transmission cooler recommended for active drivers.

Drive Options: Rear-wheel drive or Intelligent AWD.

Weak Points and Common Issues

When buying a used Infiniti QX70 (FX), pay attention to:

Engines:

• V6 (VQ35/VQ37): Monitor oil consumption, valve cover gaskets, throttle body cleanliness.

• V8 (VK45/VK50): Check for cylinder scoring, oil consumption, cooling system condition.

• Diesel V6 (V9X): Most high-risk; inspect timing chain, bearings, and EGR system.

Transmission:

• 7-speed automatic generally reliable but test for smooth shifts. Look for jerks, delays, or noises. Ensure transmission cooler is present.

Suspension:

• Control arm bushings and ball joints are consumables, often requiring replacement after 60–120k km.

• Wheel bearings may produce noise; replaced with hub assembly.

• Steering rack may develop leaks or play over 150k km.

• Brakes: Pads and discs wear faster due to weight and sporty driving.

Body and Paint:

• Paint is soft, prone to chips. Possible corrosion on suspension parts and select body panels, especially in regions with road salts.

Electronics:

• Generally reliable, but older models may have minor glitches (e.g., frozen electronics in cold weather, xenon light ballast issues).

Interior:

• Quality materials, but seats and steering wheel may show wear on high-mileage vehicles.

Why a VIN Check is Essential

The Infiniti QX70 (FX) is often purchased for spirited driving, may have been in accidents, or imported from abroad, particularly the USA. A VIN check is a crucial tool for a safe purchase.

Real Mileage: Used QX70s are often subject to odometer tampering. A VIN report from vincode.online reveals the actual mileage recorded at service centers and during registrations.

Accident History: A VIN check provides full details of past accidents, damage extent, and even auction photos for cars imported from the US. This helps avoid vehicles with hidden or major repairs.

Service Records: Proper maintenance is critical for engine and transmission longevity. VIN reports often include service history, known issues, and mileage during service.

Recalls: The QX70 (FX) was subject to Takata airbag recalls and other technical service campaigns. A VIN check confirms whether all necessary updates were completed.

Legal Status: Ensure the vehicle isn’t stolen, under lien, or has other legal complications.

Tips for Buying a Used Infiniti QX70 (FX)

Choose Your Engine:

• V6 (FX35/37/QX70 3.7) is generally less problematic.

• V8 is more powerful but higher risk.

• Diesel (FX30d/QX70 3.0d) is economical but potentially costly to repair.

Start with a VIN Check: Order a full report on vincode.online to screen risky vehicles before an in-person inspection.

Professional Diagnostics: Conduct a full computer check at a specialized Infiniti/Nissan service center.

Engine:

• Inspect oil consumption, V8 cylinder condition, and diesel timing chain/EGR system.

Transmission:

• Check fluid level and quality, smoothness, and absence of jerks. Ensure the extra cooler is installed.

Suspension:

• Examine control arms, bushings, bearings, and steering rack condition.

Test Drive:

• Evaluate engine and transmission performance, ride quality, handling, and absence of unusual noises.

Visual Inspection:

• Look for accident repairs, corrosion, and interior wear.

The Infiniti QX70 (FX) is a charismatic, sporty crossover that remains stylish and dynamic even today. It offers excellent driving dynamics and comfort, but like any used premium vehicle, it requires careful inspection, particularly for engine and transmission condition.

Make your purchase safe and informed by starting with an Infiniti QX70 VIN check on vincode.online.