2021 Kia K5 Fuel System Problems

57 owners have reported fuel & propulsion system problems with the 2021 Kia K5 to NHTSA — 34% of all 169 complaints for this model year. The typical failure happened around 115,000 miles. That ranks #1 of 4 K5 model years for fuel system complaints (a typical year has 44). 2 related recalls have been issued.

57complaints
115ktypical miles
2related recalls
0crashes
0fires
1injuries

Which parts fail

  • Storage › Tank assembly
    1

Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).

Mileage when the problem started

  • Under 25k
    00%
  • 25k–50k
    00%
  • 50k–75k
    217%
  • 75k–100k
    325%
  • 100k–150k
    650%
  • 150k+
    18%

Owner reports

Selected complaints filed with NHTSA by 2021 Kia K5 owners, lightly cleaned up (personal details are redacted by NHTSA).

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. …

111,000 miles · Jul 2026

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. …

86,000 miles · Mar 2025 · 1 injury

The contact owns a 2021 Kia K5. The contact received notification of NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline); however, the part to do the recall repair was not yet available. The contact stated that while driving approximately 70 MPH, upon further inspection the fuel level was lowering unexpectedly. The check engine warning light was illuminated. The vehicle was taken to a local Auto Zone and was scanned with an OBD2 scanner and diagnosed with a recall-related failure. The vehicle was taken to a local dealer, where it was diagnosed with an expanded fuel tank; however, the vehicle was not repaired because the dealer was short-staffed. The dealer associated the failure with NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). The manufacturer was made aware of the failure; a case was filed; however, no assistance was provided. …

90,000 miles · Jul 2026

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.

120,000 miles · Feb 2026

The contact owns a 2021 Kia K5. The contact stated that the check engine warning light remained illuminated with DTC: P0471 displayed. The vehicle was included in NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline) and was taken to the dealer for the recall repair where the dealer replaced the check valve. After receiving the recall repair, the check engine warning light remained illuminated with DTC: P0471 displayed. The vehicle was returned to the dealer, who diagnosed that the Exhaust Pressure Sensor was causing the Exhaust Gas Recirculation (EGR) Sensor to fail and needed to be replaced. The vehicle had not been repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 52,000.

52,000 miles · Jan 2026

The contact owns a 2015 Kia K5. The contact received notification of NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). The contact stated that days before the vehicle was scheduled for an unknown recall repair, while refueling, the contact observed gasoline pouring out of the tank. The vehicle was taken to a dealer, where it was diagnosed, and determined that the fuel tank had expanded due to fumes being trapped inside. The vehicle was not repaired due to parts not being available for the repair. The contact stated that the manufacturer has exceeded a reasonable amount of time for the recall repair. The manufacturer was notified of the failure. The failure mileage was approximately 70,000.

70,000 miles · Feb 2025

The contact owns a 2021 Kia K5. The contact stated that while driving approximately 55 MPH, the fuel gauge suddenly went from one-half tank to empty. The fuel level displayed 120 miles to empty. The contact attempted to refuel the vehicle but was unable to add fuel to the tank. The contact also stated that the oil warning light and the TPMS warning light was illuminated. The contact associated the failure with NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 119,185.

119,000 miles · Jul 2026

The contact owns a 2021 Kia K5. While driving at an undisclosed speed, the contact heard a loud explosion coming from the rear of the vehicle, and there was a dragging sound coming from the vehicle. The contact stated that the rear seat raised up into the air with children seated in the seat. The contact became aware of fuel leaking and that the fuel tank was hanging down. The vehicle was towed to the residence and was later driven to a KIA dealer. The manufacturer was made aware of the failure. The approximate failure mileage was 116,000.

116,000 miles · Dec 2025

The contact owns a 2021 Kia K5. The contact stated that while driving approximately 55-60 MPH, the fuel tank expanded. There were no warning lights illuminated. The vehicle was towed to the local dealer, where it was determined that the fuel tank had expanded, and that the vehicle was unrepairable. The vehicle was not repaired. The dealer offered a buyback. The manufacturer was not contacted. The failure mileage was approximately 115,000.

Storage › Tank assembly · 115,000 miles · Jul 2026

The contact owns a 2021 Kia K5. The contact stated that there was an abnormal odor of fuel. The check engine light was illuminated. The contact received the recall notice for NHTSA Campaign Number: 25V794000 (Fuel System, Gasoline). An unknown local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 200,000.

200,000 miles · Mar 2026

Related recalls

Fuel system, gasoline

NHTSA recall 25V-794 · Nov 17, 2025 · 250,547 vehicles

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.

Fuel system, gasoline › Delivery › Hoses, lines/piping, and fittings

NHTSA recall 21V-519 · Jul 8, 2021 · 21,575 vehicles

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.

Fuel System complaints in other K5 years

2021202220232024202520265744555
Fuel System complaints per model year, Kia K5.

Frequently asked questions

How common are fuel system problems on the 2021 Kia K5?

NHTSA has 57 complaints about the fuel & propulsion system of the 2021 Kia K5, 34% of the model year's 169 complaints. The component named most often is storage › tank assembly (1 mentions).

Is there a recall for 2021 Kia K5 fuel system problems?

Yes — NHTSA recall 25V-794 (fuel system, gasoline, Nov 17, 2025); NHTSA recall 21V-519 (hoses, lines/piping, and fittings, Jul 8, 2021). Recall repairs are free at authorized dealers.

At what mileage do 2021 Kia K5 fuel system problems start?

Half of the complaints with a recorded mileage happened before about 115,000 miles.

Is it dangerous?

Owners linked 0 crashes, 0 fires and 1 injury to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.

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.