2006 Infiniti FX35 Problems: 15 Known Issues

On the 2003-2007 Infiniti FX35, early VQ35DE-equipped FX35 models are known for a whining or supercharger-like noise caused by wear in the timing chain guides and related front timing components. Infiniti issued service information for replacing the primary timing chain, guides, tensioners, and sprockets when abnormal noise is present, most commonly on earlier production years.

On the 2003-2008 Infiniti FX35 VQ35DE, the first-generation FX35 uses the VQ35DE, an engine known for oil consumption once ring wear sets in. On the FX the more common mechanism reported by owners is oil pulled through the PCV system: the narrow baffle channels in the passenger-side valve cover gum up and the PCV valve passes liquid oil into the intake, coating the throttle body and intake with oil and burning it. Owners report losing several quarts between changes (one 2003 owner lost more than 3 quarts every 3-4 months; another 2005 at 105k was 2.5 quarts down when the cats failed). Running low on oil on this engine also feeds the timing-chain and catalyst problems. Rate is worse on pre-2007 engines.

On the 2003-2008 Infiniti FX35, on first-generation FX35 models with the automatic transmission cooler integrated into the radiator, internal radiator failure can allow coolant and ATF to mix. Owners report radiator tank cracking or internal cooler failure, which can quickly damage the transmission if not caught early.

On the 2003-2008 Infiniti FX35, every first-generation FX35 is covered by the Takata passenger-side frontal airbag inflator recalls. The non-desiccated PSAN inflators can rupture on deployment after long-term humidity and heat exposure, sending metal fragments at occupants. The FX was recalled repeatedly as coverage expanded: 15V226 and 15V287 (2015 regional expansions), 16V349 (zones A and B), 17V028, 20V008 (all remaining non-desiccated inflators), and then 21V139 (R20C2) for 2006-2008 FX35/FX45 that received a replacement airbag module whose cushion was folded incorrectly and can tear on deployment.

On the 2003-2012 Infiniti FX35, the FX35 commonly develops intermittent failures of the camshaft position sensors and sometimes the crankshaft position sensor, causing stalling, hard starts, or limp operation. Heat and age degrade the sensor electronics, and this issue is widely reported across Nissan/Infiniti VQ applications of the era.

On the 2003-2008 Infiniti FX35, first-generation FX35/FX45 (shared with the G35 and Murano) chronically burn out the door lock actuators. One door stops responding to the fob or the master switch, and owners commonly end up replacing three or all four over the life of the car; an actuator failing in the locked position can leave a door that will not open at all. A failed actuator can also confuse the body control logic so a window drops after locking. Dealers quote $400-500 per door, or over $2,000 for all four.

On the 2003-2012 Infiniti FX35, the FX35 is well known for front-end clunks, loose steering feel, and uneven tire wear caused by worn front lower control arm bushings, compression rod bushings, and sway bar end links. The vehicle's weight and sporty suspension tuning accelerate bushing wear, especially on rough roads and higher-mileage examples.

On the 2003-2012 Infiniti FX35, premature front wheel hub bearing wear is one of the most widely reported FX35 faults across both generations, with owners reporting failures anywhere from 30,000 to 100,000 miles and frequently both sides within a short interval. The bearing is pressed into a sealed hub unit, so the whole hub assembly is replaced. Symptoms are a roaring or humming that rises with speed and changes when weaving lane to lane. Dealers quoted around $500 per side; aftermarket hubs run ~$130 each.

On the 2003-2012 Infiniti FX35, a common Nissan/Infiniti issue on this era of FX35 is inaccurate fuel level readings caused by wear or contamination of the fuel level sending unit inside the tank. Owners report the gauge sticking, dropping suddenly, or showing empty with fuel still in the tank, sometimes accompanied by a check engine light.

On the 2003-2012 Infiniti FX35, infiniti service bulletin ITB00-024I applies to all Infiniti vehicles and defines brake judder as vibration felt through the vehicle, steering wheel or brake pedal while braking. The bulletin identifies rotor thickness variation and/or rotor runout as the cause; brake-pedal pulsation and, in severe cases, steering-wheel oscillation can result.

On the 2003-2008 Infiniti FX35 VQ35DE, first-generation FX35s commonly set P0420 and/or P0430 (catalyst efficiency below threshold, bank 1/bank 2) as the two close-coupled converters degrade, often between 80,000 and 130,000 miles. Contributing causes on this engine are oil consumption coating the catalyst and rich running from failed coils/plugs or sensor faults. Dealers quote about $1,500 per converter plus labor, with the OEM manifold-integrated cats being the expensive part. Aftermarket high-flow cats compatible with the G35/350Z are a common lower-cost route, and replacing downstream O2 sensors alone often does not clear the code.

On the 2003-2012 Infiniti FX35, both FX35 generations use the Jatco RE5R05A 5-speed automatic. Owners report a harsh or lurching 4-to-3 downshift when slowing, shudder or flare on 4th/5th engagement, and in worse cases a transmission stuck in 3rd or 4th that will not select 5th with the manual mode showing only 'D'. Infiniti addressed the shift-quality complaints with a TCM reprogram; the second-gen owner community reports the reflash 'cured' shifting complaints. Cars that go beyond shift quality into limp mode usually have solenoid/valve body faults, and the solenoids are serviced only as a complete valve body assembly.

On the 2003-2008 Infiniti FX35 VQ35DE, first-generation FX35 owners frequently trace a power steering fluid loss to the pump's shaft seal and O-rings, or to the high-pressure line where it joins the pump or rack, typically around 85,000-130,000 miles. Fluid sprays onto the belt and lower engine, the reservoir runs low, and the pump whines or the steering goes heavy at low speed. Rack boot leaks (failing inner rack seals) are the other, more expensive source. A worn or leaking pump run dry will also take out the belt.

On the 2003-2008 Infiniti FX35, on 2003-2008 FX the rear hatch stops releasing from the exterior button or key fob while the interior emergency release still works. Failures are usually intermittent at first (one owner reported sporadic failure at 90,000 miles) and progress to complete non-response. The cause is the electric latch release motor/actuator in the liftgate, whose brushed motor commutator fouls; some owners find that unlocking a front door manually will briefly let the hatch open, pointing to the actuator rather than the switch.

On the 2003-2008 Infiniti FX35, first-generation (S50) FX35 dashboards develop raised bubbles, blisters and a sticky, melting surface, typically starting around the navigation screen and air vents and spreading across the top pad. The adhesive and vinyl skin fail under heat and UV exposure, so Sun Belt cars are hit hardest and earliest (often by 50,000 miles or 4-6 years of age). Nissan knew of complaints by 2006, faced a class action (Gourley v. Nissan North America), and ultimately extended the dashboard warranty to 96 months / unlimited miles from production date and replaced more than 45,000 dashboards. Owners whose dashes bubbled after the 8-year window were routinely denied.