2018 Infiniti Q50

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 NHTSA review.

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.”

Within one month of purchase, the airbag warning light illuminated and has remained on continuously. A separate dealership later confirmed the airbag system is defective and may not deploy in an accident. This is a serious safety defect that was not disclosed to me at the time of sale. Additional Issues: •On July 14, 2025, I dropped the car off for prolonged starting issues. I was told the vehicle had six faulty fuel pumps/injectors. •I have not had possession of the car since July 14. •On August 30, 2025, I received an email from Nissan of Orange Park stating the car was “completed and ready.” When I called the next day, I was told the car was not at Nissan at all, but at Infiniti, with no clear repair status or timeline. Concern: This is a federal safety defect. I request NHTSA’s review and investigation into Infiniti/Nissan’s handling of defective airbag systems in this vehicle and the misleading communication surrounding repairs.

The contact owns a 2018 Infiniti Q50. The contact stated that while driving at an undisclosed speed, the "Low Oil Pressure - STOP", message was displayed, and the contact stopped driving the vehicle. The contact stated that while starting the vehicle, the engine was abnormally loud. The contact stated that the low oil pressure warning light was illuminated. The vehicle was towed to an independent mechanic, who diagnosed a failure with the timing chain. The vehicle was not repaired. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 107,000.

My coolant reservoir kept on going empty, I took to dealer for service they replaced the radiator fan module and told me my engine was not porous. I was driving and my engine ended up stalling, turned off while I was driving in the freeway at a high speed cause me to almost lose control of my vehicle because everything stopped working. It looks like an inner rod failed possibly because of the coolant going into engine.

2/1/2023 we took our 2018 Q50 to the Infiniti dealership and service center. The engine was having issues, increased RPMs while simultaneously experiencing loss of power/stalling. This was experienced by both my wife and I. Infiniti's determination was the Mass Air Flow Sensor and told us the issue was not covered by the platinum, bumper to bumper extended warranty they sold us due to the warranty only covering mechanical issues, not electrical. The service tech was able to get costs waived as factory warranty covered such events to 75k miles. We picked the car up on 2/8/2023. On 3/18/2023 the car was again towed to the dealership. The intermittent issue that was thought to be the Mas Air Flow Sensor and electrical, hit suddenly and with such force the car would not run whatsoever and stalled out on a very busy 50 MPH Parkway and my wife had to maneuver her way to safety with cars flying all around her. No obvious sign of electrical mass failure, lights still on, etc. On 3/24/2023 I received a call and was told the engine needed to be replaced, the cost was $32k, and that the warranty’s fine print says that the warranty will only cover up to the fair market value of the car, which they determined to be about $21k. I’m responsible for their faulty engine & poor mechanical workmanship? I was sent pictures of debris and springs sitting in the bottom of the dropped oil pan and a separate photo clearly showing a disintegrating cam shaft / lower engine area adjacent to the oil pan. Catastrophic and very avoidable failure (this is not an engine in a military vehicle or motorsports vehicle). I believe the problem was never the Mass Airflow Sensor, it was the alloys used in this area of the engine that were failing. This failure is not the first for Infiniti (have been reading forums)