The 2019 Q50 is built on Infiniti's proven FM platform with generally reliable powertrains, but the 2.0T Mercedes-sourced engine and 7-speed auto have notable catastrophic failure modes, while the Red Sport's 3.0T V6 runs strong but demands meticulous maintenance. The 3.7L V6 is the most bulletproof option.
2.0L Turbo (M274) Catastrophic Engine Failure
Occasional · high severityTypical onset: 50,000-90,000 mi
Symptoms: sudden knocking or rattling from bottom end, loss of oil pressure warning, metal shavings in oil, complete seizure in worst cases
Fix: Mercedes M274 engine suffers connecting rod bearing failures and piston ring land fractures, often without warning. Requires complete engine replacement or full rebuild with updated pistons and bearings. 25-35 labor hours for R&R and rebuild.
Estimated cost: $8,000-15,000
7-Speed Automatic Transmission Oil Cooler Failure
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: transmission fluid in coolant (strawberry milkshake in overflow), transmission slipping or harsh shifts, overheating warnings, coolant loss with no external leaks
Fix: Internal oil cooler inside radiator develops cracks, cross-contaminating coolant and ATF. Requires radiator replacement, transmission flush (sometimes full rebuild if contamination severe), and coolant system flush. 6-8 hours labor if caught early, 20+ hours if transmission damaged.
Estimated cost: $1,200-2,500 early / $4,500-8,000 with trans damage
Direct Injection Carbon Buildup (All Engines)
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: rough idle, especially when cold, misfires on cold start, reduced power and fuel economy, check engine light with multiple misfire codes
Fix: All Q50 engines use direct injection with no port injection cleaning cycle. Intake valves accumulate carbon deposits requiring walnut blasting or chemical cleaning. 4-6 hours labor depending on engine access (V6 is easier than turbo 4).
Estimated cost: $600-1,200
Transmission Mount Failure
Common · low severityTypical onset: 50,000-80,000 mi
Symptoms: clunking when shifting from park to drive, vibration at idle in gear, excessive drivetrain movement on acceleration, visible tearing or fluid leak from mount
Fix: Hydraulic transmission mount deteriorates, especially on Red Sport models with higher torque. Straightforward replacement, but requires supporting transmission. 2-3 hours labor.
Estimated cost: $400-700
Red Sport 3.0T Fuel System Pre-Ignition (LSPI)
Occasional · high severitySymptoms: sudden loud knock under moderate acceleration (1500-3000 rpm), loss of power, check engine light with knock sensor codes, in severe cases, cracked pistons or bent rods
Fix: Low-speed pre-ignition events on VR30DDTT can crack piston ring lands. Caused by poor fuel quality, wrong oil spec, or aggressive driving in low RPM/high load conditions. Requires engine teardown to assess damage; often needs all pistons and rings replaced. 20-30 hours for full repair.
Estimated cost: $6,000-12,000
Backup Camera Failure
Occasional · low severityTypical onset: 40,000-90,000 mi
Symptoms: intermittent black screen when shifting to reverse, distorted or fuzzy image, complete camera failure, warning message on display
Fix: Rear camera assembly fails due to moisture intrusion or internal electronics fault. Subject to NHTSA recall for some VINs. Replacement camera unit and reprogramming required. 1-2 hours labor.
Estimated cost: $300-600
Steering Rack Electronic Assist Issues (DAS)
Occasional · medium severityTypical onset: 50,000-100,000 mi
Symptoms: steering warning light illuminated, heavy steering or complete loss of power assist, steering pulls to one side, erratic assist response
Fix: Direct Adaptive Steering system (steer-by-wire on certain trims) experiences electronic module failures or position sensor faults. Often requires complete rack assembly replacement as individual components not serviceable. 4-6 hours labor.
Estimated cost: $2,500-4,000
Buy the 3.7L V6 or Red Sport 3.0TT with documented maintenance; avoid the 2.0T Mercedes engine unless you have a solid warranty and low miles.
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.