2013 INFINITI FX50

Typical onset: 80,000-130,000 mi

Symptoms: Cold-start rattle lasting 3-5 seconds that progressively worsens, Metal shavings in oil during changes, Timing chain noise under load or at idle, Eventually: catastrophic bearing failure, rod knock, complete seizure

Fix: The VK50 engine has a defective timing chain oil gallery gasket that leaks internally, starving the timing components and bearings of oil. Early intervention requires timing chain/tensioner/guide replacement (12-16 hours labor). If bearing damage has occurred, you're looking at full engine rebuild or replacement (25-35 hours labor). Many owners opt for low-mileage used engines due to cost.

Estimated cost: $4,500-7,500 for timing components alone; $12,000-18,000 for engine replacement/rebuild

Typical onset: 70,000-110,000 mi

Symptoms: Pink or milky transmission fluid (coolant mixing), Transmission slipping or harsh shifts, Overheating transmission temperature warnings, Coolant loss with no external leaks

Fix: The internal transmission cooler (inside the radiator) develops leaks, allowing coolant and ATF to cross-contaminate. Requires radiator replacement, complete transmission fluid flush with new filter, and often transmission replacement if contamination went unnoticed (8-10 hours for cooler/flush; 16-20 hours if transmission is damaged). Catch it early by inspecting fluid color religiously.

Estimated cost: $1,800-3,200 for radiator and flush; $6,500-9,500 if transmission is cooked

Typical onset: 60,000-90,000 mi

Symptoms: Clunking when shifting from Park to Drive or Reverse, Vibration at idle in gear, Excessive drivetrain movement visible during acceleration, Transmission 'slap' over bumps

Fix: The hydraulic transmission mounts fail internally, allowing excessive drivetrain movement. Replacing both mounts takes 3-4 hours labor. OEM mounts are strongly recommended as aftermarket versions fail prematurely on this heavy V8/trans combo.

Estimated cost: $800-1,400

Typical onset: 90,000-140,000 mi

Symptoms: Rough idle or misfires (often multiple cylinders), Hard starting especially when hot, Fuel smell in cabin or engine bay, P0171/P0174 lean codes alongside misfire codes

Fix: Direct-injection fuel injectors develop internal leaks or clogging. Individual injector replacement is 1.5-2 hours each, but they often fail in groups. High-pressure fuel pump can also fail (6-8 hours labor). Nissan updated injector design in later years. Full set replacement with updated parts is common fix.

Estimated cost: $2,200-3,800 for all eight injectors; $1,500-2,200 for high-pressure pump

Typical onset: 80,000-120,000 mi

Symptoms: Harsh or delayed shifts especially 2-3 or 3-4, Limp mode activation with P0745 or P0868 codes, Erratic shifting behavior when transmission is cold, Shuddering during lockup converter engagement

Fix: The 7-speed's valve body solenoids stick or fail. Requires transmission pan drop, valve body removal, and solenoid pack replacement (6-8 hours labor). Often combined with fluid/filter service. Infiniti released updated valve body programming; reflash should be done simultaneously.

Estimated cost: $1,800-2,900

Typical onset: Any mileage (heat-related)

Symptoms: No-start condition with no crank (starter won't engage), Stalling while driving with immediate no-restart, Issue occurs hot, resolves when engine cools, P0335 or P0340 codes stored

Fix: The crank position sensor fails when heat-soaked, leaving you stranded. Replacement is only 1.5-2 hours labor but requires accessing sensor behind timing cover area. Many techs replace both crank and cam sensors simultaneously as preventive measure given labor overlap.

Estimated cost: $450-750 for both sensors