2021 Hyundai Sonata: True Cost, Problems & Verdict
130 NHTSA owner complaints · 4 recalls · data-computed verdict. No opinions — public data only.
Editor's note
The sixth-generation Sonata (2011–2014) is the car that brought Hyundai's Theta II engine problem into the open. Connecting-rod bearing failure in the 2.0 and 2.4-litre engines leads to knocking, stalling and, in the worst cases, fire; Hyundai recalled 2011–2014 Sonatas in 2015 and 2017, extended the engine warranty, installed a knock-sensor detection system, and in 2020 paid a civil penalty to the federal regulator over the timing of the recalls. Read the full note on the model page. 2021 specifically: a year the record favours — 130 complaints, score 83/100. The caveats in the note apply to other years of this nameplate more than to this one.
Read the guide
The first-year rule: why the launch year of a new generation is the one to avoid, including 2021 — written and signed by Adir Trabelsi, 2026-09-01.
Owner complaints: 130 filed with NHTSA
Complaints per year on the road: 26.0
What owners say
Verbatim reports filed with the United States safety regulator (NHTSA) by owners of this exact model year. Public record.
The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA 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 …
The Left blinker switch keeps going in and out, working about 50% of the time. Both the light and the blinker sound do not turn on. When getting it checked out at an auto repair shop, the maintenance tech said this was more and more common for 2021 sonatas and it was not due to anything I did. It was a multifunction switch problem.
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.
Recalls: 4 campaigns (2 severe)
| Campaign | Component | Summary |
|---|---|---|
| 22V746000 | Power Train:Automatic Transmission | Hyundai Motor Company (Hyundai) is recalling certain 2021-2022 Santa Fe, Sonata, Veloster N, 2022 Santa Cruz, Elantra N, and Kona N 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. |
| 21V524000 | Fuel System, Gasoline:Delivery:Hoses, Lines/Piping, And Fittings | 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. |
| 25V796000 | Fuel System, Gasoline | 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. |
| 21V00M000 | Visibility:Windshield | Hyundai Motor America (Hyundai) is recalling certain 2020-2021 Santa Fe, 2021 Sonata, and Elantra vehicles. During manufacturing, the windshield may not have been properly bonded to the vehicle, allowing it to detach in a crash. |
What it costs to buy — and what owning it really takes
Class-level estimates, priced as a mid-size car of its model year, re-priced to your country. Not a quote, not a valuation of one specific car — condition, mileage and options move it. How these are computed.
What it costs to run
EPA combined 27 MPG · estimated annual fuel cost $2,300
Re-priced automatically from your country's retail fuel, electricity and parts indices — change country in the bar at the top. Estimates; see methodology.
What this car's problems cost to fix
Ranked by the components owners of this exact model year actually complain about. Each figure is flat-rate labour hours x the local shop rate plus a parts band — an estimate of what this kind of failure costs, not a quote, and not a prediction that this car will need it. Formula.
- Engine34 complaints · typical job: Cooling-system or timing-drive repair (6.0 h labour + parts)$1,040–$2,220
- Unknown Or Other32 complaints · typical job: Diagnosis and mixed repair (2.0 h labour + parts)$360–$940
- Power Train23 complaints · typical job: Transmission service or clutch-pack repair (7.0 h labour + parts)$1,290–$4,040
- Fuel/Propulsion System20 complaints · typical job: Fuel pump or injector replacement (3.5 h labour + parts)$680–$1,620
- Electrical System17 complaints · typical job: Alternator, battery-drain or body-module diagnosis and replacement (3.0 h labour + parts)$540–$1,310
- Fuel System12 complaints · typical job: Fuel pump or injector replacement (3.5 h labour + parts)$680–$1,620
Other Hyundai Sonata years
FAQ
What is the most common problem with the 2021 Hyundai Sonata?
The most-reported issue in NHTSA complaint data is Engine (34 complaints in our indexed sample).
Is the 2021 Hyundai Sonata a good used car to buy?
Our data verdict is BUY with a reliability score of 83/100, computed from 130 NHTSA complaints and 4 recall campaigns. See the verdict card for the top reasons.
How much does it cost to fix the 2021 Hyundai Sonata's most common problem?
34 of the NHTSA complaints filed against the 2021 Hyundai Sonata sit in the Engine group — more than any other component on this model year. The representative job there is cooling-system or timing-drive repair: about 6.0 hours of labour plus parts, roughly $1,040–$2,220 at a US independent shop and re-priced to your country at the top of the page. It is an estimate of what this class of failure costs, not a quote for this car.
What does a 2021 Hyundai Sonata cost to run per year?
About $4,164 a year in fuel or energy plus the maintenance band — roughly $20,820 over five years, before purchase price, insurance and depreciation. Figures come from available EPA fuel-economy data and industry maintenance averages, and are re-priced to your country.
Does the 2021 Hyundai Sonata have recalls?
Yes — NHTSA lists 4 recall campaign(s) for the 2021 Hyundai Sonata, 2 of them touching fire, crash or stall risk, the most recent recorded 06/10/2022. Check this car's VIN at nhtsa.gov/recalls before you buy.
Compare with
Other midsizes of about the same age.
What will a 2021 Hyundai Sonata really cost YOU per year?
Fuel, maintenance band and depreciation — computed from public data in 10 seconds.
Open the true-cost calculatorData sources
Complaints & recalls: NHTSA ·
Fuel economy: EPA fueleconomy.gov ·
Scoring: our published methodology.
Maintenance bands are industry-average estimates (AAA Your Driving Costs, CarMD index) — labeled estimates, not measurements.
Last updated: 2026-10-04.
Moderate evidence — 130 complaints, 4 recalls on record
- 130 NHTSA complaints on record (26.0/yr of exposure) — better than a typical year of this model (46.5/yr)
- 4 recall campaigns, 2 touching safety-critical systems