DESCRIPTION OF SAFETY DEFECT & IMMEDIATE HAZARD:My 2021 Hyundai Sonata SEL is currently exhibiting the most severe, catastrophic symptoms of the fuel tank expansion defect covered under the federal safety agency Campaign 25V796000. The fuel tank has expanded so drastically that it physically warped the structural interior of the cabin, violently popping the rear passenger seat completely out of its assembly while the vehicle was in motion. Furthermore, there is a constant, heavy, raw gasoline odor inside and around the vehicle. The vehicle is a documented, active fire, explosion, and vapor inhalation hazard. It is currently physically located at Sterling Hyundai in Lafayette, LA.DESCRIPTION OF MANUFACTURER NON-COMPLIANCE & REFUSAL TO REMEDY:Hyundai Motor America and Sterling Hyundai are in direct violation of their legal obligation to provide a safe, accessible remedy or interim safety accommodations under federal recall guidelines. An Executive Case Manager from Hyundai Corporate has officially refused to provide a direct-billed rental vehicle or a dealer loaner.Initially, a third-party rental vehicle was provided. However, that vehicle was compromised in an accident and wrecked through absolutely no fault of my own. Despite my lack of fault, Hyundai Corporate and the dealership are now explicitly using that accident to refuse any further direct-billed rental accommodations or dealer loaners.Instead, they are demanding that I pay out-of-pocket for a rental vehicle at a rate of $60/day for a repair process expected to take multiple weeks, knowing I do not possess the upfront financial means to cover these costs. By imposing this insurmountable financial barrier due to an accident I did not cause, Hyundai has effectively stranded me. Because I must maintain my livelihood and have no other means of transportation, Hyundai’s bad-faith refusal to direct-bill an accommodation is actively forcing me to retrieve and operate a verified, explosive fire hazard.REMEDY SOUGHT:I request that the NH
2021 Hyundai Sonata fuel system problems
34 complaints (25% of all complaints for this car). Typical mileage when it fails: 80,484. 1 crash reported.
- owner complaints
- 34
- of this car's complaints
- 25%
- typical mileage
- 80,484
- crashes
- 1
- recalls
- 2
Which part fails
- Fuel injection system: injectors1
- Delivery: fuel pump1
At what mileage
Complaints by mileage at the time of the problem.
Hyundai Sonata fuel system problems in other years
Specific symptoms reported on the 2021 Hyundai Sonata fuel system
Phrases found in the owners' own descriptions, so one complaint can mention several symptoms.
Related recalls
Fuel system, gasoline
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain 2020-2023 Sonata 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.
- Risk
- A melted fuel tank can leak, increasing the risk of a fire.
- Remedy
- Dealers will inspect and replace the check valve. The fuel tank assembly will be inspected for damage and replaced if necessary. Additionally, dealers will inspect and update the engine control unit software. All repairs will be performed as necessary, free of charge. Owner notification letters were mailed beginning March 13, 2026. Owners may contact Hyundai customer service at 1‑855‑371‑9460. Hyundai's number for this recall is 286. Vehicle Identification Numbers (VINs) involved in this recall became searchable on on November 19, 2025.
Recall number 25V796000 · Recall details
Fuel system, gasoline: delivery: hoses, lines/piping, and fittings
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Santa Fe and Sonata vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.
- Risk
- A fuel leak increases the risk of a fire.
- Remedy
- Dealers will inspect and tighten, or replace the fuel pipe as necessary, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact Hyundai customer service at 1‑855‑371‑9460. Hyundai's number for this recall is 207.
Recall number 21V524000 · Recall details
What 2021 Hyundai Sonata owners say
Most recent owner complaints, unedited.
The contact owns a 2021 Hyundai Sonata. The contact received notification of the federal safety agency Campaign: 25V796000 (Fuel System, Gasoline); however, parts were on back order. The contact stated that while driving at an undisclosed speed, the vehicle jerked with an abnormal gasoline odor inside the vehicle. An unknown warning light was temporarily illuminated. Upon further inspection, the contact became aware that the fuel level had dropped. The vehicle was taken to a local dealer where it was diagnosed with an expanded fuel tank. The contact stated that the O2 sensor, spark plugs, and ignition coils were replaced by a local independent mechanic; however, the failures persisted. The contact had headaches while driving the vehicle. Medical attention was not needed. The manufacturer was made aware of the failure. The failure mileage was approximately 100,000.
The contact owns a 2021 Hyundai Sonata. The contact received notification of the federal safety agency Campaign Number: 25V796000 (Fuel System, Gasoline); however, the part to do the recall repair was not yet available. The contact stated that while driving at an undisclosed speed, the vehicle independently accelerated and decelerated while the accelerator pedal was depressed. The check engine warning light was illuminated. The vehicle was towed to a local dealer where it was diagnosed with an expanded frame due to an expanded fuel tank. The vehicle was deemed too expensive to repair per the local dealer and was towed for a buy-back. The manufacturer was made aware of the failure, but no assistance was provided. The failure mileage was approximately 55,000.
I took my vehicle in for the safety recall due to an expanding fuel tank on 08/03/2026. I received my vehicle back on 8/12/2026. Hyundai performed an improper repair on the vehicle that will not correct the fuel tank expansion. They replaced the same check valve that was replaced last time I brought the vehicle in for recall on 11/20/2024 repair order # 107221 at Jones Hyundai of Belair. This valve did not and will not correct the fuel tank expansion issue. The expansion issue is caused by fuel getting past the check valve and entering the purge control system. The correct repair is to replace the fuel tank and the purge control system, as the check valve has already allowed fuel to bypass it and enter the system causing the expansion issue. . Replacing the valve that failed & allowed fuel into the system & caused the tank to expand will not correct the issue caused by the failed valve. My fuel tank has not decompressed. I still have the same problem I brought the vehicle in for because the repair Hyundai advised the federal safety agency on was NOT performed.
Gas tank expansion and pcv melted. Car smells like gas when I was driving earlier, and my garage was flooded with the fumes of gasoline.
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the fuel gauge indicated that the tank was half full. The contact stated that the gauge erroneously indicated that the tank was empty, and the check engine warning light was illuminated. The vehicle was driven to the gas station, and while attempting to refuel the vehicle, the fuel did not go into the tank. The vehicle was towed to the residence. The vehicle was later towed to the dealer, where it was diagnosed with a failed fuel system and a failed fuel tank. The contact was informed that the fuel system and fuel tank needed to be replaced. The vehicle was not repaired. The contact was informed that the failure was associated with the unrepaired recall. The contact was informed that the vehicle was a fire risk. In addition, the contact was informed that there was a hole in the fuel tank that caused the fuel to leak out of the fuel tank. The contact was informed that the parts were ordered to repair the vehicle. The contact received notification of the federal safety agency Campaign Number: 25V796000 (Fuel System, Gasoline). The manufacturer was not made aware of the failure. The failure mileage was approximately 50,200.
Engine revving at a complete stop. Surging engine while braking. I was forced to put into neutral when stopping. I had check engine prior that read P049D85. It went away. The Hyundai dealer said to be the EGR valve. Nick Hayes at D'Arcy Hyundai and Hyundai Motor America (HMA) agreeing to a 75% goodwill split of cost to repair.
The contact owns a 2021 Hyundai Sonata. The contact received notification of the federal safety agency Campaign Number: 25V796000 (FUEL SYSTEM, GASOLINE); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The vehicle was taken to the local dealer, and the contact was informed that the fuel tank was swollen and needed to be replaced. The vehicle was not yet repaired. The failure mileage was 80,484.
At approximately 130,000 miles, vehicle developed and internal coolant leak caused by a failed Exhaust Heat Recovery System (EHRS) in the center muffler assembly, matching TSB 23-EM-009H - a known manufacturing defect documented by Hyundai. Coolant has been slowly leaking internally into the exhaust system. The authorized Hyundai dealership initially failed to diagnose the internal leak and told me there was no leak and wanted to send me home. After pushing back, the internal leak was confirmed. If not caught, this defect could result in engine overheating or complete engine failure without warning. Hyundai Motor America has denied goodwill coverage despite this being a documented manufacturing defect.
I took my car to dealer to repair recall. Dealer told me if it failed they would keep car and report stolen if I tried to take it. They failed it. I didn't trust them based on their report it stolen statement. I had the police get my car back. I took it to another dealer where it passed recall easily. I believe they wanted my car for a customer, and tried to get away with this ruse.
Questions about the 2021 Hyundai Sonata fuel system
Does the 2021 Hyundai Sonata have fuel system problems?
Owners have filed 34 complaints about the fuel system of the 2021 Hyundai Sonata, 25% of all its complaints.
At what mileage do 2021 Hyundai Sonata fuel system problems start?
The typical (median) mileage in owner complaints is 80,484 miles.
Was there a recall on the 2021 Hyundai Sonata fuel system?
Yes, 2 recalls: 25V796000, 21V524000. Check your VIN to see if your car still needs the free repair.
What year does the Hyundai Sonata have the most fuel system problems?
The Hyundai Sonata model years with the most fuel system complaints are 2013 (213 complaints), 2011 (135 complaints) and 2012 (117 complaints).
Other 2021 Hyundai Sonata problems
Engine 35Transmission 25Electrical 18Visibility 12Driver assistance 10Airbags 4Body 4Brakes 4Acceleration 2Seat belts 2Seats 2Steering 2Suspension 1
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