Most common 2021 Kia K5 problems
Share of the 169 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Kia K5 complaints by model year
Best K5 years: 2024. Years to avoid: 2025, 2023. Compare all years →
2021 Kia K5 recalls (6)
Fuel system, gasoline
Kia America, Inc. (Kia) is recalling certain 2021-2024 K5 vehicles. A damaged check valve can allow air to enter the fuel tank, causing it to expand and contact hot exhaust components, melting the tank.
Remedy: Dealers will replace the check valve. The fuel tank will be inspected for damage and replaced as necessary. All repairs will be performed free of charge. Owner notification letters were mailed January 16, 2026.
Air bags › Side/window › Curtain
Kia America, Inc. (Kia) is recalling certain 2021-2023 K5 vehicles. The side curtain air bags may have been installed incorrectly, causing them not to deploy properly in the event of a crash.
Remedy: Dealers will inspect and reinstall the side curtain air bags, as necessary, free of charge. Owner notification letters were mailed April 7, 2023. Owners may contact Kia customer service at 1-800-333-4542.
Power train › Automatic transmission
Kia Motors, Inc. (Kia) is recalling certain 2021-2022 Sorento and 2021-2023 K5 vehicles. The vehicle's "fail-safe" limited-mobility drive mode may be impaired, when prompted by a transmission oil pump malfunction, which can result in a complete loss of drive power.
Remedy: Dealers will inspect and replace the transmission, as necessary. Dealers will also update the transmission control unit software. All repairs will be performed free of charge.
Fuel system, gasoline › Delivery › Hoses, lines/piping, and fittings
Kia Motor America (Kia) is recalling certain 2021 Sorento and 2021-2022 K5 vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.
Remedy: Dealers will inspect and tighten, or replace the fuel pipe as necessary, free of charge. Owner notification letters were mailed July 21, 2021. Owners may contact Kia customer service at 1-800-333-4542.
Lane departure › Lane keep › Steering assist
Kia Motors America (Kia) is recalling certain 2021-2022 K5 vehicles equipped with 2.5L T-GDI engines. The Rack-Mounted Motor Driven Power Steering (R-MDPS) system lacks the ability to diagnose communication faults.
Remedy: Dealers will update the R-MDPS software, free of charge. Owner notification letters are were mailed June 24, 2021. Owner may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC213.
Air bags › Sensor › Occupant classification › Front passenger
Kia Motors America (Kia) is recalling certain 2021 Telluride, K5, and Forte vehicles. The Occupant Classification and Detection System (OCS/ODS) unit may not detect the presence of a child restraint system in the front passenger seat.
Remedy: Kia will notify owners, and dealers will replace the OCS/ODS unit, free of charge. The recall began March 18, 2021. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC207.
What 2021 Kia K5 owners say
Fuel & propulsion system all 57 →
The contact owns a 2021 Kia K5. The contact received notification of NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). The vehicle was taken to a dealer for the recall repair. The contact was struggling to receive updates on the status of the vehicle. The contact spoke with a service clerk and was informed that the repair was going well and that only one recall test remained. However, a supervisor later called and stated that the recall repair could not be completed. The vehicle could not be repaired. The vehicle was no longer functional due to a high risk of catching fire from fuel tank swelling caused by the recall defect. The contact stated that prior to the dealer visit, the vehicle had no issues but became inoperable. The vehicle was not repaired, and the dealer stated that the vehicle could not be repaired. The manufacturer was made aware of the issue. …
The contact owns a 2021 Kia K5. The contact stated while her daughter was driving 60 MPH, there was an abnormal sound coming from the engine, when the gas tank expanded, and the back seat popped up. The contact stated that two teenagers were in the back seat, and one was injured. The contact's daughter pulled over and waited for a short while. The vehicle was restarted; however, the vehicle drove slowly. The vehicle was taken to a dealer; however, the vehicle was not diagnosed. The vehicle was taken to another dealer; however, no cause for the failure was found. The contact was informed that the seat had moved two inches. The contact stated that the vehicle was not repaired because the frame of the seats could be damaged. The vehicle was not repaired. The manufacturer was notified of the failure. The vehicle remained at the dealer and had not been driven since. …
Electrical system all 46 →
The contact owns a 2021 Kia K5. The contact stated that while driving at various speeds, the Lane Assist feature would illuminate without other vehicles nearby. The contact also stated that the vehicle would independently switch lanes independently; causing the contact to forcefully adjust the steering wheel into the desired lane to prevent a potential crash. The contact manually disabled the features; however, the features independently reactivated. In addition, the defroster failed to operate as needed which obstructed her vision due to fog on the windshield. The vehicle was initially taken to a dealer, but the contact was offered no assistance. The contact then took the vehicle to Kia of Irvine (45 Oldfield Building B, Irvine, CA 92618) where two mechanics acknowledged the failure while test driving the vehicle. …
Kia has a known issue with the HVAC blower motor circuit on this vehicle model. They have issued a warranty extension related to relocating the blower motor fuse to another circuit in the fuse box, due to potential burning of fuse(s). After executing this extended warranty fuse-relocation-procedure, our blower motor relay burned and was replaced twice by separate Kia dealers. Kia is now claiming that our entire wire harness needs to be replaced at our own cost. It is quite obvious that any wire harness issue is now very dangerous (electrical arcing and melting) and was caused by the original motor circuit issue. …
Engine & cooling all 32 →
The contact owns a 2021 Kia K5. The contact stated that while driving approximately 45 MPH, the vehicle jolted forward three times and then lost power. The contact stated that while driving at approximately 60 MPH, the check engine warning light illuminated. The contact steered the vehicle into an independent mechanic and the vehicle was inspected, and there was oil all over the engine compartment. The vehicle was taken to a dealer, where it was diagnosed, and determined that an unknown sensor was inoperable and needed to be replaced. The vehicle was repaired, but the failure recurred the same day the vehicle was retrieved. The vehicle was taken to the same dealer where it was diagnosed, and determined that the valve cover needed to be replaced. The vehicle was repaired, but the failure reoccurred nine times, and the valve cover was replaced each time. …
The contact owns a 2021 Kia K5. The contact stated that there were failures with the spark plugs. While driving at an undisclosed speed, the vehicle shuddered, and the engine sputtered. The contact stated that fuel spewed out of the filler neck while refueling the vehicle, and the fuel gauge incorrectly indicated that the fuel tank was empty after refueling. Additionally, there was an abnormal egg and sulfur odor coming from the vehicle with the check engine warning light intermittently illuminated. The contact stated that the vehicle was taken to a local dealer and inspected under NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). During the inspection, the seats were damaged. The vehicle was not repaired. The manufacturer was notified of the failure and was negotiating a buyback. The failure mileage was approximately 120,000.
2021 Kia K5 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 1.6L 4-cyl turbo | 8-speed automatic | FWD | 29 / 38 / 32 |
| 1.6L 4-cyl turbo | 8-speed automatic | AWD | 26 / 34 / 29 |
| 2.5L 4-cyl turbo | 8-speed dual-clutch | FWD | 24 / 32 / 27 |
EPA ratings. Class: Large car.
Frequently asked questions
Is the 2021 Kia K5 a good car?
There isn't enough complaint history for the K5 to compare model years reliably. So far owners have filed 169 complaints with NHTSA.
What is the most common problem with the 2021 Kia K5?
The fuel & propulsion system — 57 complaints, 34% of all complaints for this model year, most often about storage › tank assembly. Next are the electrical system (46) and engine & cooling (32).
How many recalls does the 2021 Kia K5 have?
There are 6 recalls for the 2021 Kia K5, the most recent from November 17, 2025 (fuel system, gasoline). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Kia K5?
The best years by complaints, compared at the same age, are 2024. Years to avoid or approach with caution: 2025 and 2023. See the full Kia K5 years comparison.
At what mileage do 2021 Kia K5 problems happen?
The median mileage reported in complaints is about 45,000 miles; 52% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.