2021 Hyundai Sonata engine problems
59 of the 189 complaints owners filed with NHTSA about the 2021 Hyundai Sonata name the engine (NHTSA’s “Engine” heading — the engine and its cooling system). Filed under the same heading: 37 manufacturer bulletins, 1 NHTSA investigation. Every figure below is a document in a federal file, linked; none is a failure rate, and none is a verdict on any one car.
What owners filed about the engine
Source: NHTSA complaint database1 of the 59 reports a crash · 0 a fire · 0 injuries. Self-reported, unverified.
Filed per year: 2021: 1 · 2022: 4 · 2023: 17 · 2024: 13 · 2025: 9 · 2026: 15
Too few of these complaints carry an odometer reading to say when the problem shows up.
189 complaints in all about the 2021 Hyundai Sonata, 15 filed in 2026. The whole picture, every system →
Counts are owner reports to NHTSA, not verified defects, and scale with how many of these were sold; nothing here is a rate. NHTSA groups complaints coarsely, so “Engine” means the same area of the vehicle, not one fault.
Across model years: Hyundai Sonata engine problems, every year on file →
In owners’ own words
Source: NHTSA complaint databaseFiled with NHTSA by the people who own these cars, about the engine. Quoted as written, with anything identifying removed; unverified reports — what was said, not a finding that it was true.
The contact owns a 2021 Hyundai Sonata. The contact stated while driving 15 MPH, the contact noticed that the passenger’s side rear seat level had become elevated. The contact stated that his daughter who was seated in the child seat head had started touching the top of the sunroof.
Antifreeze is coming out of the exhaust. Heater is only blowing cold air. Repair shop said it is a common problem with the Hyundai hybrids. Was told I had to take it back to the dealership. The y repair shop said this is very common and is wondering why a recall has not been issued by the NTHSB. Dealership has been unresponsive
My vehicle's heat stopped working suddenly. A short while later, I received and overheat warning for the engine. I had to stop repeatedly on the shoulder of the highway to allow the car to cool so I could move it to a safe space at the next exit.
I was on the highway going 60 mph then all of a sudden my vehicles rpm's jumped way up to 8 and completely lost power was on I-45 in Conroe thankfully I was in the slow lane. I have attached pictures of my dash so I could get proof this time. I had to wait 7 minutes for the car to do anything. It also burned all of my engine oil.
While driving, engine alerted that it was overheating. Pulled over and coolant was very low, so I refilled it and then while driving to my family's garage to use the lift, saw white exhaust smoke. Took it to an independent mechanic, and in the ~10 mile trip there, over a quart of coolant had been burned off.
What is on file about the engine
Source: NHTSA recalls, investigations and manufacturer communicationsNHTSA investigation
- DP22003 Loss of Motive Poweropened Sep 12, 2022 · closed Dec 12, 2023
- The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints i…
37 manufacturer bulletins filed under this heading
- 26-EE-003H TSB Service bulletinApr 18, 2026
- Some vehicles may exhibit difficulty starting in cold weather. This bulletin provides the procedure to perform an inspection on the starter magnetic switch for potential freezing and, if necessary, replace the starter magnetic switch (solenoid) assembly.
- 26-EM-003H TSB Service bulletinFeb 5, 2026
- Some Sonata (DN8, DN8A) vehicles may have DTCs P218100, P2181F0, and/or P2181F1 (Cooling System Performance) set in the Engine Control Module, resulting in an illuminated Check Engine warning lamp. Follow the procedure in this TSB to replace the Integrated Thermal Management (ITM) module and update both the Engine Control Module (ECM) and Transmission Control Module (TCM) if applicable. Follow the
The 2 newest are listed; every one is on the model year’s page. Quote the document number at a service desk — it is a diagnosis the maker has already written down.
Trouble codes named on this system
Codes a bulletin or an owner’s complaint about the 2021 Hyundai Sonata names on this model year; a code with a record of its own links it.
Common questions
Source: NHTSA complaint database, recalls and manufacturer communicationsAre engine problems common on the 2021 Hyundai Sonata?
They are documented: NHTSA holds 59 owner complaints naming the engine on this model year (31% of everything owners filed about it), and 37 manufacturer bulletins, 1 NHTSA investigation are filed under the same heading. Whether it is a problem on one particular car is a diagnosis, not a count, and a count says nothing about how many were sold.
Is there a recall for the engine on the 2021 Hyundai Sonata?
No recall campaign is filed under this heading for this model year (there are 4 filed under other headings). A bulletin is not a recall: it carries no federal duty to repair for free.
When do engine problems show up on the 2021 Hyundai Sonata?
Too few of the complaints carry an odometer reading to say. The model year's page shows the mileage curve across every system where it can.
What does NHTSA's "Engine" heading cover?
The engine and its cooling system. Owners choose the heading when they file, so it says which area of the vehicle the complaint is about, not which part failed.