2021 Kia K5 transmission problems

Filed Oct 12, 2026 · Transmission · OK

From the get-go seemed to have trouble with transmission once in a while Little jerk when shifting gears, reported this, they could find nothing. It has become a lot worse. It has caused the car to shut down into limp mode with engine light on. So I had a problem from the beginning with my new car. But when they check it, they can’t find a problem. So I’m just checking to see if anybody else with this car make, model, year have reported anything the same.

Filed Sep 23, 2026 · Electrical, Transmission · NC

65k miles. Started driving, 20 minutes into driving i was stopped at a round about then I went to accelerate and nothing happened my engine revd really loud and after about 10 seconds my car jolted forward and I was able to accelerate, this would happen every time I stopped and anytime a wanted to accelerate to another gear

Filed Jul 30, 2026 · Fuel system, Transmission · GA

Recall NNK post-repair failure. Dealership: Kia of Valdosta (RO# XXX). After ECU update NNK-02-0118, my K5 suffered a severe loss of acceleration and torque. The car cannot safely merge on highways. The dealer’s own live scan data sheet proves that at 4,997 RPM under full load, the Turbo Recirculation (Dump) Valve reads "OFF". The factory tool key explicitly states (OFF = Open). The service manager is misreading the tool, claiming "OFF" means closed, and refuses to fix it. The boost gauge only rises under heavy floor acceleration, proving an uncalibrated boost leak. I have uploaded a photo of the technician's data sheet directly to the attachments and will also drop link to videos of my car in normal and sport mode. I have also opened Kia Corporate Case #XXX. I demand a corporate Regional Technical Manager review this data and authorize a Turbocharger Recirculation Valve (RCV) and Wastegate Adaptation Relearn at an alternate dealer...... 1. [XXX] 2. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 4, 2026 · Engine, Lights · 56,000 miles · KS

The contact owns a 2021 Kia K5. The contact stated that the driver-side turn signal became inoperable. The vehicle was shifting hard and/or not shifting at all. While driving at unknown speeds, the vehicle shut down. The turn signal and brake lights were illuminated. The contact stated there was a recall for the federal safety agency Campaign Number: 25V794000 (Fuel System, Gasoline). The vehicle was taken to the local dealer for diagnosis of the signal light. The vehicle was repaired, but the failure recurred. The BBB was contacted who filed a claim. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 56,000.

Filed May 7, 2026 · Engine, Transmission · 86,017 miles · IL

The contact owns a 2021 Kia K5. The contact stated while driving at an undisclosed speed, the vehicle shuddered. The check engine warning light was intermittently illuminated. The failure occurred on several different occasions. The vehicle was taken back to the residence. The vehicle was taken to a dealer to get a diagnosis however, the failure cause was unidentifiable. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 86,000.

Filed Oct 14, 2025 · Transmission · 15 miles · CA

The contact owns a 2021 Kia K5. The contact stated that while his daughter was driving approximately 15-20 MPH, the engine revved and the gears in the transmission unexpectedly failed. In addition, the vehicle failed to accelerate as intended while depressing the accelerator pedal. No warning lights were illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. Due to the safety concerns, the vehicle was no longer driven and remained parked at the residence. The manufacturer was not informed of the failure. The failure mileage was unknown.

Filed May 27, 2025 · Transmission · 98,000 miles · FL

The contact owns a 2021 Kia K5. The contact stated while driving approximately 30-40 MPH, while the transmission was shifting gear, the vehicle started sputtering and jerking. The contact stated that the failure occurred while shifting from 1st gear to 2nd gear, and from 2nd gear to 3rd gear. There were no warning lights illuminated. The vehicle was taken to the dealer who diagnosed the vehicle with an erratic gear shift with a grinding sound coming from the transmission. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 98,000.

Filed May 17, 2025 · Airbags, Fuel system · IL

I recently purchased a Kia k5 2021 gt line awd one month later I noticed there was recall I take to the dealership they let me know it will only take a few hours (3) and I can pick up later the same they call me 3h later and let me know sorry this case is going to take a few weeks and I should pick up rental car and they will pay for my rental so I did I come back one month later nothing as been done they just tell me to wait and they can’t release due to the safety recall the tank has swelled up it has been 3mont now and they still haven’t done anything to the car and I can’t sell the vehicle cause they won’t release it

Filed Mar 22, 2025 · Transmission · NC

very bad antifreeze smell under hood dealer said normal not healthy to smell that its in all of this model car in multiple years needs a recall to force kia to fix this unhealthy problem. 3/1/25 is when i bought this car. thankyou

Filed Sep 29, 2024 · Brakes, Engine · MN

While driving on my way home from work my , brakes became extremely hard to press down on and then my service engine light came on this all occurred on 7/31/2024. So the very next day I took my vehicle to a Kia dealership which was 8/1/ 2024 to find out what was causing this to happen. The technician stated that they would have to put it on a machine and run a diagnostic on it. I asked the technician while they were doing that to change the oil. I also realized that the oil light for my vehicle has NEVER came on since I purchased the car. So the technician did the diagnostic and stated that my vacuum pump had went out but he couldn’t tell me why or how this had happened. I then took the vehicle to my parents house and left it there in the garage for a few weeks to have second opinion done. I then took it to another Kia dealership and they stated there was no vacuum to the brake booster and said there was a broken camshaft and metal pieces were in the engine and the engine needed to be replaced. Again I asked what caused all of this and no one could give me an answer. I had only had the car a 1 1/2 years and don’t understand what caused all of this and I now have a car that I can no longer drive.