Kia K5, Hyundai Sonata Gas Tank Swelling, Expanding – Lawsuit Investigation 

Attorneys working with ClassAction.org are investigating whether a class action lawsuit can be filed amid reports of gas tank swelling in certain Kia K5 and Hyundai Sonata vehicles.

A local news station has published multiple articles about the cars’ fuel tanks expanding unexpectedly, causing the backseats to “pop up” and the vehicles to emit a sound akin to a loud bang or explosion. It’s possible that the problem may pose a safety hazard, with one dealership reportedly telling a woman she was “lucky” to have brought the car in without issue after the gas tank in her 2022 Kia K5 expanded.

Now, attorneys want to speak with drivers of 2021, 2022, 2023 and 2024 Hyundai Sonata and Kia K5 vehicles who’ve experienced gas tank expanding or swelling as they work to determine whether a defect is to blame. It’s possible that a class action lawsuit could be filed to force a recall and recover money for loss of vehicle value, the cost of repairing any damage to the cars, and more.  

Was There a Sonata or Kia K5 Gas Tank Recall?

To date, there has been no fuel tank recall for the K5 or Sonata vehicles. In April or May of 2024, Kia reportedly initiated a “voluntary service campaign” – which is not the same as a recall – for certain 2021 to 2024 Kia K5 vehicles equipped with a Gamma II 1.6L T-GDI engine over the possibility of fuel tank swelling. A bulletin about the service campaign states that the fuel tanks may expand due to an issue with the PCSV check valve, which causes “pressurized air to flow into the fuel tank.” The document states that the Kia K5 fuel tank issue may cause the check engine light to come on, the engine to run rough and the driver to have trouble refueling the vehicle.

Kia drivers have posted on Reddit that they received letters offering a free inspection and fix, with one user noting, however, that it is “kind of weird how they’re pushing it as voluntary instead of urging all those models to be brought in” as would happen in a traditional recall.

WSOC-TV, which was among the first to report on the Kia K5 and Hyundai Sonata fuel tank issue, writes that, as of June 17, 2024, Hyundai had not announced a similar program.

Gas Tank Expanding Problems: Kia K5, Sonata Drivers Complaints  

The following is a sampling of online complaints and stories about the fuel tank issue [sic throughout]:

When I was driving I heard big boom sounds in my backseat which ended up being my fuel tank which expanded and raised the back seat. It slowly got worse impacting my car’s fuel sensor and the tank expanded more and more I drove.”
— 2021 Kia K5 driver, NHTSA ID Number: 11594072

I was driving home yesterday and experienced a loud pop in the back of the car and found the backseat had lifted because the gas tank had expanded I am at the dealership right now…I would like to trade the car in because I don’t trust the car anymore…”
— 2022 Kia K5 driver, NHTSA ID Number 11588860

I am a[n] owner as well of a 2021 sonata SEL PLUS 1.6T and my gas tank is expanding and Hyundai corporate is refusing to fix anything. I have been told by my Hyundai dealer that the car is deemed unsafe and is a[n] actual bomb. My back seats of my vehicle pop up now about 6" away from the frame and has been misshaped…”
— 2021 Hyundai Sonata driver, Reddit.com

It basically sounded like an explosion, like a bomb went off, and then it kind of shook the car.”
— 2023 Kia 5 driver, Alfrida B., as told to WSOC-TV

How Could a Class Action Lawsuit Help?

If filed and successful, a class action lawsuit could force Hyundai and Kia to issue a recall over the Sonata and K5 fuel tank issue. It could also help drivers recover money for repair costs, vehicle damage and loss of vehicle value. 

Before commenting, please review our comment policy.