2018 Infiniti Q50 Problems: 7 Known Issues

On the 2014-2018 Infiniti Q50, the Q50's 2.0t uses the Mercedes-Benz M274 turbocharged four, shared with the C300 and GLC300. The timing chain and the camshaft adjusters (variable valve timing phasers) wear faster than the engine's design life, with problems commonly surfacing somewhere around 80,000 miles and reported as early as 60,000 on neglected cars. The first symptom is a brief metallic rattle on cold start as oil pressure builds and the tensioner takes up slack. Left alone, chain stretch throws off cam timing, sets correlation codes, and in the worst cases the chain skips teeth or breaks, which on this interference engine destroys valves and pistons. Extended oil change intervals and low oil level accelerate the wear.

On the 2016-2019 Infiniti Q50 VR30DDTT, early-production VR30DDTT engines leave the factory with the A/C compressor pulley bracket slightly out of plane with the rest of the accessory drive. The misalignment makes the serpentine belt track toward the edge of the smooth idler pulley, where it frays, walks off, and eventually shreds. Because a single belt drives the water pump, alternator, and A/C compressor, losing it means immediate charging failure and rapid overheating, and the shredded belt can damage the pulleys, alternator, and water pump on its way out. Infiniti issued TSB ITB18-012 covering the alignment inspection and correction procedure. Nissan later revised the lower smooth idler pulley with raised lips to keep the belt captive — the design that shipped on the RZ34 Z.

On the 2016-2018 Infiniti Q50 VR30DDTT, the turbocharger center bearing on the 3.0L twin-turbo VR30DDTT can wear prematurely and let engine oil leak internally past the bearing seals into the exhaust and intake tracts. Oil burning in the exhaust produces heavy white or blue smoke, fouls the catalyst, and trips the MIL. In severe cases the turbo loses boost control and the internal components come apart, which can send debris downstream. Infiniti acknowledged the defect with a turbocharger emission warranty extension covering 2016-2018 Q50 and 2017-2018 Q60, extending coverage on the turbocharger assembly to Full Useful Life — 10 years or 120,000 miles, whichever comes first — when the failure presents as white smoke or an oil leak with a MIL-on condition.

On the 2014-2018 Infiniti Q50, the M274 four-cylinder in the 2.0t burns noticeably more oil than owners expect, and consumption climbs with mileage. Reports commonly describe roughly a quart per 3,000 miles once the car passes 60,000 miles, with worse cases burning a quart every 1,500 miles. The usual contributors are piston ring wear and coking, valve stem seal hardening, and the crankcase ventilation system pulling oil vapor into the intake. Because the Q50 has no oil dipstick on this engine — the level is read through the instrument cluster — owners often do not notice the loss until the low-oil warning appears, and running the engine chronically low is what turns oil consumption into timing chain and bearing damage.

On the 2016-2018 Infiniti Q50, q50 sedans with the 2.0L turbo four use a saddle-shaped fuel tank with a transfer system that moves fuel between the two lobes. Incorrect Fuel Pump Control Module software allows the main tank lobe to run too low to feed the engine even though usable fuel remains on the other side and the gauge still shows fuel available. The result is an engine stall while driving, typically at lower indicated fuel levels. NHTSA campaign 17V476000 covers 2016-2018 Q50 and 2017 Q60 with the 2.0L engine; the recall began August 29, 2017.

On the 2014-2018 Infiniti Q50, on rear-wheel-drive Q50 sedans the two-piece propeller shaft can develop fatigue cracks and fracture in service. When the shaft breaks the car loses all drive power without warning, and because the parking pawl in the transmission is no longer connected to the rear wheels the vehicle can roll away when shifted to Park unless the parking brake is set. NHTSA campaign 24V470000 covers 2014-2018 Q50 two-wheel-drive vehicles along with several related M and Q70 models; Infiniti's internal campaign numbers are R24A5 and R24A7. Owner notification letters were mailed August 13, 2024. AWD cars are not covered by this campaign.

On the 2014-2026 Infiniti Q50, the dual-screen InTouch infotainment system suffers from significant lag, freezing, and occasional black screens. The system uses an outdated processor that struggles with modern navigation and connectivity demands.