2018 Infiniti Q50 problems

Filed Sep 22, 2026 · Airbags · TX

Systemic defect front passenger seat occupancy sensor failure triggering an illuminated airbag warning light.

Filed Jul 7, 2026 · Airbags, Seat belts · 34,000 miles · SC

The contact owns a 2018 Infiniti Q50. The contact stated while driving at an undisclosed speed, the air bag warning light illuminated. The vehicle was taken to the dealer, where the contact was informed that the front passenger seat and passenger seat belt needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 34,000.

Filed Jun 8, 2026 · Airbags · 59,200 miles · FL

The contact owns a 2018 Infiniti Q50. The contact stated that while driving at an undisclosed speed, the front passenger Occupant Classification System (OCS) sensor became inoperable. The vehicle was taken to the dealer, where it was diagnosed that the front passenger OCS sensor had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 59,200.

Filed May 5, 2026 · Driver assistance, Electrical · NY

I am submitting this complaint regarding a safety defect in my 2018 Infiniti Q50, which was manufactured prior to May 1, 2018. Despite matching the make, model, and production timeframe associated with an existing Infiniti recall for backup camera failures, my specific vehicle is not included in the recall population. The backup camera in my vehicle intermittently fails to display an image or presents a blank or distorted screen when the vehicle is placed in reverse. This defect significantly impairs rear visibility and increases the risk of a collision, particularly in situations involving pedestrians, children, or obstacles that may not be visible through mirrors alone. The backup camera is a critical safety feature, and its failure directly compromises safe vehicle operation. The exclusion of my vehicle from the recall is concerning, given that it shares the same model year, platform, and manufacturing period as those already identified as defective. This suggests that the defect may be more widespread than currently acknowledged. A malfunctioning backup camera is not a minor inconvenience as it creates a clear and preventable safety hazard. I urge the federal safety agency to review this issue and consider expanding the scope of the existing recall to include all affected 2018 Infiniti Q50 vehicles, including those manufactured before May 1, 2018, that are currently excluded. Additionally, I encourage further investigation into the consistency and reliability of the backup camera systems in this model line. This complaint is submitted not only to address my individual vehicle but also to contribute to a broader understanding of a potential safety defect that may affect other drivers. I believe that multiple reports of similar issues will help prompt appropriate action to ensure public safety. Thank you for your attention to this matter.

Filed Mar 19, 2026 · Electrical · 54,000 miles · CA

Odometer Fraud. The contact purchased a 2018 Infiniti Q50. It was discovered that there were three separate mileage discrepancies. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 50,370; however, at the time of registration, it was discovered that the mileage had been rolled back from 54,000 to 28,630 miles. The mileage before the vehicle was purchased was 47,650.

Filed Jan 7, 2026 · Engine, Fuel system · CA

Filing this complaint regarding a safety-related defect involving the turbocharger system on my 2018 INFINITI Q50. The vehicle has approximately 46,000 miles and is 8 years old. INFINITI/Nissan has acknowledged through its own Technical Service Bulletins (TSBs) that turbocharger failure on 2016–2018 Q50 3.0T vehicles is a known defect. Nissan’s documentation identifies issues such as turbo oil seal leaks, reduced engine power, smoke, and potential catastrophic engine failure, and provides an extended warranty of up to 10 years or 120,000 miles due to the safety risks associated with sudden power loss. My vehicle experienced turbocharger failure consistent with these known defects, resulting in loss of engine power, which presents a serious safety hazard, particularly during highway driving, merging, or intersections. Sudden loss of propulsion increases crash risk and endangers vehicle occupants and others on the road. In some cases, turbo failure can occur with little or no warning, further increasing risk. The failure was confirmed by INFINITI/Nissan service departments, and the vehicle remains available for inspection. CarMax insurance approved the engine repair, acknowledging mechanical failure; however, they declined to approve turbocharger repair specifically because INFINITI has issued a known TSB and extended warranty covering turbo failure, deferring responsibility to the manufacturer. Despite the vehicle being within the extended warranty limits, Nissan denied coverage, claiming the vehicle has a “branded title.” This claim is unsupported by VIN reports, the loan originator, and CarMax’s own title search prior to leasing all confirm the title is not branded. Nissan has provided no documentation supporting its assertion. Nissan N.A. reviewed and closed the matter despite the known safety defect and lack of evidence for the title claim. Represents a safety-related defect and improper denial of a manufacturer-recognized safety remedy, warranting the federal safety agency review.

Filed Dec 10, 2025 · Engine · AL

Leak in the turbo causing oil to burn and create smoke from the exhaust

Filed Nov 28, 2025 · Engine · GA

The serpentine belt on my 2018 Infiniti Q50 Sport became contaminated with oil immediately after dealer turbo replacement at the end of August 2025, causing the belt to slip, shred, and be pulled into the engine. This resulted in sudden loss of essential engine functions and poses a significant safety hazard. This failure was caused by improper repair at the dealership.”

Filed Oct 15, 2025 · Brakes, Engine · 88,000 miles · NY

The contact's son owns a 2018 Infiniti Q50. The contact stated that soon after purchasing the vehicle, there was an abnormal screeching sound coming from the brakes while depressing the brake pedal. There was no warning light illuminated. The contact's son took the vehicle to an independent mechanic to have the brake pads and rotors replaced. However, less than one month after the replacement of the pads and rotors, there was an abnormal grinding sound coming from the front passenger’s side brakes. The mechanic was notified of the issue, and the contact was informed that the brake calipers might also need to be replaced. The contact stated that while driving at various speeds, the engine temperature gauge indicated that the engine was hot(H), with white smoke coming from the exhaust pipes. The vehicle was taken back to the independent mechanic, but the mechanic was unable to determine the cause of the failure. The vehicle was taken to another independent mechanic and the contact's son was informed that the head gasket had failed, and an engine replacement was recommended. The dealer was notified of the failure, and the contact was informed that there were no recalls or warranty on the vehicle. The manufacturer was also notified of the failure and provided the same information as the dealer. The vehicle was not repaired. The failure mileage was approximately 88,000.

Filed Oct 8, 2025 · Airbags · AZ

The airbag/srs light is on. I've read on multiple forums that this is a common occurrence with this model and year of Infiniti. It did not come on as a result of any accident/incident.