2026 Jeep Grand Cherokee L

I am the owner of a 2026 Jeep Grand Cherokee L equipped with the 2.0L Hurricane 4 Turbo engine. At approximately 3,500 miles, the vehicle experienced a spark plug failure/breakage. The vehicle was taken to Nyle Maxwell dealership in Austin, Texas, where a spark plug was found broken and was replaced under warranty on 5/15/2026 after a lengthy wait for the parts of 11 days. This same failure occurred a second time at approximately 4,900 miles on 7/13/2026. The vehicle was again taken to the Nyle Maxwell dealership for repair. Both failures occurred while operating the vehicle on 87 octane regular unleaded fuel, which is the fuel grade stated as acceptable in the owner’s manual. I am concerned this is a widespread issue, as other owners of this same engine report similar spark plug failures using 87 octane fuel, per online owner forums. I am filing this complaint to document the pattern and request that NHTSA investigate.

While driving my 2026 Jeep Grand Cherokee, the check engine light began flashing (a flashing, rather than steady, check engine light typically indicates an active engine misfire). At or around the same time, the vehicle began shaking/vibrating noticeably, consistent with the misfire condition indicated by the flashing light. Separately, I experienced a failure of the vehicle’s push-button Start/Stop ignition system. When attempting to shut the engine off by pressing the Start/Stop button, the engine did not turn off as expected. The button had to be pressed several times before the engine finally powered off.

While driving from Tampa to Miramar Beach, Florida, the vehicle operated normally on the highway. However, shortly after exiting the highway and driving in slow traffic, the engine temperature gauge suddenly rose into the red zone, and the air conditioning automatically shut off. I immediately pulled over and allowed the vehicle to cool. The engine temperature returned to normal, and after the engine cooled completely, I found that the coolant reservoir level was only slightly below the MIN mark. There are no visible coolant leaks, no check engine light, and no warning messages currently displayed.

I was stuck on the Hot way for 45 minutes cause my car was heating up. It’s been in shop four times for heating up on the fourth time I took it in. I was stocked because my electrical started going out. The speedometer started just going around my electrical on my dash started going from heat to cold my seat controls then it started of the dash panel are going to ABS and going to different things showing the speedometer showing the mileage on the car it just started doing its own controls so and then my speedometer just called going fast and went back to deal so and didn’t blacked out so I videotaped everything

I purchased a brand new 2026 Jeep Grand Cherokee L Summit in April 2026. At approximately 1,205 miles, while traveling with my wife and [XXX] child in [XXX] , the vehicle suddenly developed a flashing check engine light and severe engine misfire condition. The engine began shaking violently, idling rough, and lost smooth drivability during operation. I scanned the vehicle using an OBD-II scanner and the PCM stored diagnostic trouble code P0302, indicating a cylinder #2 misfire. Due to concern for vehicle safety and possible engine damage, the vehicle was towed to Vaden Chrysler Dodge Jeep RAM for diagnosis. The dealership later advised me that the spark plug in cylinder #2 had cracked porcelain and that the vehicle requires spark plug replacement. The dealership also stated they were awaiting authorization/approval from Stellantis before proceeding with repairs. This failure occurred extremely early in the vehicle’s life and caused my family to become stranded during travel. A flashing check engine light indicates an active misfire severe enough to potentially damage emissions components and raises concerns about engine reliability and safety. I am concerned there may be a manufacturing defect, ignition system defect, spark plug defect, improper assembly issue, or another underlying engine-related problem. I am submitting this complaint so the issue is documented in case other owners experience similar early engine failures or ignition-related problems on this vehicle platform. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)