2025 Kia K4 Powertrain (other) Problems

I purchased my 2025 Kia K4 in March 2025. Approximately two months after purchasing the vehicle, around May 2025, I began experiencing serious and recurring safety issues. While driving, the vehicle intermittently loses acceleration and becomes unresponsive when I press the gas pedal. When this occurs, I have to pull over, turn the vehicle off, and restart it before I can continue driving. On other occasions, the vehicle has unexpectedly shut off and restarted on its own while I was driving. The dashboard also goes completely black during these incidents. I have taken the vehicle to an authorized Kia dealership for inspection, but I was informed that the dealership could not duplicate the problem. The issues have continued, leaving me concerned about the safety of the vehicle. I previously requested that Kia repurchase or replace the vehicle, but my request was denied. I am requesting that NHTSA investigate these recurring loss-of-power, stalling, and electrical issues because they create a serious risk of a collision.

NHTSA ID

11770717

Incident

May 27, 2026

Transmission slippage, rpms rev higher then mph, hesitates at red lights and stop signs

NHTSA ID

11746968

Incident

Jun 26, 2026

To whom this may concern, I was using my cruise control on my way to work. I usually set it to 80 because police are okay with that speed on I-75. I braked before my automatic brakes hit after I got cut off. I pressed resume in the cruise control and it accelerated pretty quick. I’ve experienced that quite a bit, but there’s been a few times that the car exceeded the set cruising speed while trying to resume. I forget it happens because it’s happened about 4 times since purchasing the vehicle. I noticed an officer on the shoulder leaving the shoulder as I got closer, and he got right behind me and cut his lights on, I look down and the cruise control shows 80 above the speedometer (photo attached taken while pulled over), BUT the arm was past the tick for 90. The officer clocked me at 92 apparently. This is the only time this issue has occurred, and I informed the officer that this happens. I have a court date set for July 9th now. I Googled to see if other owners have this problem. There are others who expressed experiencing this in their K4s and K5s. The AI tool explained the following • "Resume" Behavior: When you press the resume button, the car attempts to get back to 80 mph as quickly as possible. This aggressive acceleration can cause it to temporarily overshoot the target speed before settling down. • Settings Sensitivity: The acceleration strength and reaction speed can be set to "Fast" in your infotainment system, causing more aggressive throttle input.

NHTSA ID

11737989

Incident

May 11, 2026

As I entered onto i4 reaching the speed of 60 miles an hour my vehicle began to make a high pitched whining noise that got louder as I pressed on the gas pedal, noise dissipated when I let off the gas pedal. Vehicle began to slow down on its own , even when applying pressure to the gas pedal, I had no choice but to pull over on i4, error message displayed “RED CAUTION EMBLEM” error message “Transmission Control Unit” Kia k4 app displayed Diagnostic Alert AT PO72200

NHTSA ID

11729395

Incident

Apr 5, 2026

Engine Failure, Engine cooling and lost power

NHTSA ID

11719127

Incident

Feb 1, 2026

When I drive over 65 mph, I feel the car lose stability, and sometimes I feel those movements in the steering wheel. Also, it doesn't show the actual tire tread depth. In addition. And there is a burning smell.

NHTSA ID

11714428

Incident

Dec 10, 2025

Sluggish acceleration, after I got an oil change a few weeks ago. No warning lights whatsoever, I’m thinking it’s the transmission , taking awhile to speed up especially on highway

NHTSA ID

11685834

Incident

Sep 8, 2025

Bought my Kia k4 2025 in February at DTLA Kia and the experience has been [XXX]. The first day driving I went up near dodgers stadium , immediately had a burnt smell. I disregarded it thinking maybe its fresh paint burning , WRONG. Till this day 4 months later my tail pipe throws a musty smell. Issue number 2 , the hesitant gas pedal. Who knows what it is maybe fuel system , transmission but daily and I mean DAILY my accelaration is poor,jerky, struggling and overall doesn't work. It has its good mornings but once I'm on the road for more than 10 minutes its back to the struggle. I've had my K4 serviced twice at Dtla service, they never once test drove the car because I was tracking the GPS almost all day for the three days they had it. Once I got my car back it tooks about 45 minutes the service advisor Jeffery Montoya was so lost on where my car was, I had to ask and ask and ask finally the guys who are out front welcoming you helped me and brought my car. That was my decision to never go back to DTLA service. Next took it to Van Nuys Kia waited to weeks from my appointment because they are moving. Finally they kept it for three days they still werent able to diagnose the issue and repair it. Modesto the advisor there said " we can't duplicate the issue''. Some how they made me pay $82 because they supposedly found plastic bags stuck to my exhuast. [XXX] I even told him I don't want it cleaned and he said oh well you authorized the diag so you have to. He reported that info to kia Corp which got my case closed and said the car works fine. NO it does not work fine. Never going. Now today [XXX] I was parking arriving somewhere the k4 said engine off shift to P while ringing the alarm from the dash. I have it on film. Second driving down [XXX] and boom car engine shuts off while car are behind me. I had to shift to p then turn the car off. Turned it back on while getting honked at and that was that. $700 a month for a lack of urgency to help me. Boo Kia. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION

NHTSA ID

11667842

Incident

Jun 18, 2025