The 2017 Q50 is a competent luxury sport sedan undermined by a problematic 7-speed automatic transmission and, on Red Sport 400 models, catastrophic twin-turbo V6 engine failures. The hybrid and base V6 models are more reliable, but transmission issues affect all powertrains.
7-Speed Automatic Transmission Valve Body Failure
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Hard shifts or delayed engagement from Park to Drive, Transmission shuddering during 2-3 or 3-4 upshifts, Limp mode with P0868 or P17F0 codes, Complete loss of forward gears
Fix: Valve body replacement requires transmission pan removal and internal work. Dealerships often push for full transmission replacement ($7k+), but independent shops can replace valve body assembly in 6-8 hours. Software updates rarely fix mechanical wear.
Estimated cost: $2,200-3,500
3.0L Twin-Turbo V6 Catastrophic Engine Failure (VR30DDTT)
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: Sudden loss of power with severe knocking noise, Metal shavings in oil, extremely low oil pressure, Check engine light with misfire codes across multiple cylinders, Coolant contamination in oil (head gasket failure)
Fix: Early VR30DDTT engines (2016-2018) suffer connecting rod bearing failures, often grenading the entire bottom end. Requires complete engine replacement or rebuild with updated bearings, pistons, and crankshaft. 40-60 hours labor for R&R and rebuild. Infiniti extended warranty on some VINs but many owners left paying out-of-pocket.
Estimated cost: $12,000-18,000
Direct Injection Carbon Buildup (All Turbocharged Engines)
Common · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Rough idle and misfires on cold starts, Gradual loss of power and fuel economy, P0300-P0304 misfire codes, Hesitation during acceleration
Fix: Direct injection engines have no fuel washing intake valves. Requires walnut blasting intake ports with manifold removed. 4-6 hours labor depending on V6 vs I4. Should be done preventively every 60-80k miles on turbocharged models.
Estimated cost: $600-1,200
Rear Driveshaft Center Support Bearing Failure
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking or vibration from underneath during acceleration, Droning noise at highway speeds (55-70 mph), Vibration worsens under load, U-joint or carrier bearing play detected during inspection
Fix: AWD models have a two-piece driveshaft with center support bearing that fails from age and heat. Entire driveshaft assembly usually replaced rather than just bearing. Subject to NHTSA recall 19V-279 for certain VINs—check if yours qualifies for free replacement. Otherwise 2-3 hours labor.
Estimated cost: $800-1,400
Electric Power Steering Rack Failure
Occasional · high severityTypical onset: 50,000-90,000 mi
Symptoms: Steering wheel suddenly becomes extremely heavy or locks up, Power steering warning light illuminated, Grinding or clicking noise when turning at low speeds, Steering pulls to one side with jerky corrections
Fix: Infiniti's Direct Adaptive Steering (DAS) system has electronic actuators in the rack that fail. Non-DAS models use conventional electric assist but still experience rack failures. Complete rack replacement required, 4-5 hours labor. Alignment mandatory afterward.
Estimated cost: $2,000-3,200
Fuel Pump Failure (Multiple NHTSA Recalls)
Occasional · high severitySymptoms: Engine stalling at any speed without warning, No-start condition with cranking but no fuel pressure, Sputtering or surging during acceleration, Check engine light with P0087 (fuel rail pressure too low)
Fix: Impeller in low-pressure fuel pump can deform and cause sudden stalling—major safety concern. Covered under NHTSA recall 20V-636 and others for specific build dates. Check recall status by VIN before purchasing. If not covered, tank drop required, 3-4 hours labor.
Estimated cost: $800-1,400
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 70,000-120,000 mi
Symptoms: Red ATF fluid pooling under car near front wheels, Transmission temperature warning light, Burnt transmission fluid smell, Low fluid level causing harsh shifts or slipping
Fix: Cooler lines corrode at crimp points or rubber sections crack from heat cycling. Lines run to radiator-mounted cooler. Replacement requires fluid drain and refill with Matic-S ATF. 2-3 hours labor. If leak goes unnoticed, transmission damage follows quickly.
Estimated cost: $400-800
Buy a 2017 Q50 2.0T or 3.7L V6 if you find one with documented transmission services and clear recall history; avoid Red Sport 400 models from this year entirely due to catastrophic engine failure risk.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.