Certain Santa Fe (TMA), Santa Fe Sport (AN), Sonata (LFA), and Tucson (TL) vehicles equipped with Theta II engines may exhibit elevated engine-out emissions. This bulletin provides instructions for updating the Engine Control Module (ECM) to address this condition.
full bulletin at NHTSA ↗2019 Hyundai Sonata engine problems
severe Owners of the 2019 Hyundai Sonata have filed 68 NHTSA complaints about the engine, typically surfacing around 60,000 miles at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Failure mileage
Complaints
68
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2015 Sonata | 412 |
| 2016 Sonata | 342 |
| 2017 Sonata | 292 |
| 2018 Sonata | 138 |
| 2019 Sonata (this page) | 68 |
| 2020 Sonata | 11 |
| 2021 Sonata | 19 |
| 2022 Sonata | 10 |
| 2023 Sonata | 13 |
3fires
1injury
When does it fail?
Of the 68 engine complaints filed for the 2019 Hyundai Sonata, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Engine accounts for 44% of every owner complaint on file for this vehicle — the dominant problem area across 8 categories tracked.
Owners have filed 68 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
Certain Santa Fe (TMA), Santa Fe Sport (AN), Sonata (LFA), and Tucson (TL) vehicles equipped with Theta II engines may exhibit elevated engine-out emissions. The California Air Resources Board has determined that these vehicles may be releasing air pollutants which exceed Federal and California standards.
full bulletin at NHTSA ↗Following completion of Service Campaign 9C2 (Theta II Emissions Improvement), certain vehicles may exhibit a brief hesitation or rough shifting condition during cold start operation. If present, this condition is expected to occur only within approximately the first 1-3 minutes after engine start, while the catalyst is reaching its normal operating temperature.
full bulletin at NHTSA ↗Following completion of Service Campaign 9C2 (Theta II Emissions Improvement), certain vehicles may exhibit a brief hesitation or rough shifting condition during cold start operation. If present, this condition is expected to occur only within approximately the first 1-3 minutes after engine start, while the catalyst is reaching its normal operating temperature.
full bulletin at NHTSA ↗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.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2019 Hyundai Sonatas report two dominant engine issues across 67 complaints: excessive oil consumption and knock/compression failures in specific cylinders.
Oil Consumption: The most common complaint is oil loss far beyond normal specs. Owners describe needing to add 1–5 quarts between scheduled oil changes spaced thousands of miles apart—some reporting a quart every 700 miles or complete loss within weeks. Several describe the low-oil warning light coming on well before the next scheduled service, while others found nearly no oil on the dipstick just days after a fresh oil change. Dealers performed oil consumption tests; results ranged from "passing" (often via overfill) to obvious failure at 2+ quarts down per 1,000 miles. Some owners were told by dealerships the loss rate was "normal" or "acceptable." A few mechanics reported seeing multiple Hyundais weekly with the same issue.
Cylinder Misfire & Compression Loss: Multiple owners report cylinder 3 misfire, cylinder 2 misfire, or complete compression loss (40% vs. normal 180%) detected after check-engine lights or rough running. A few owners mention piston ring defects or damage; one owner reports a visible crack in the oil pan at the drain-plug weld with no impact history.
Resulting Failures: Stalling on highways, limp-mode activation, knock-sensor codes, engine fires (at least two cases), extreme sludge buildup, and complete engine seizure forcing replacement. Spark-plug and coil replacement, combustion chamber cleaning, and subsequent starter failures are documented. One replacement engine failed within days and required further work.
Warranty & Repair Barriers: Many complaints detail denial of coverage due to mileage thresholds (60,000–100,000 miles depending on program), second-owner status, or invoking "maintenance neglect" without evidence. Dealers have demanded $600+ combustion cleaning or full engine replacement ($7,000–$8,000+) before Hyundai Corporate would approve any claim. Some owners cite TSB references (20-01-002H, 20-01-004H, 23-EM-008H) and mention an active class-action lawsuit involving Theta II GDI engines.
Same Hyundai Sonata engine reports on nearby years: 2016 · 2017 · 2018 · 2021
Failure modes owners describe
Excessive Oil Consumption (Internal Leak)
Engine burns or leaks oil internally at rates far exceeding normal specifications—often 1+ quart per 700–1,000 miles or complete loss within days of oil change. No visible external leaks in most cases.
When: Begins between 5,000 and 40,000 miles; complaints span vehicles from 11,000 to 150,000 miles at time of reporting.
Symptoms owners cite: Low-oil or oil-pressure warning light illuminates well before scheduled service; Dipstick shows little to no oil days after fresh oil change; Owner must add 1–5 quarts between services; Oil sludge buildup noted by mechanics; No visible leaks underneath vehicle
Codes mentioned: P0302 (Cylinder 2 Misfire), P0303 (Cylinder 3 Misfire), Generic knock-sensor codes
Repairs/costs cited: Oil consumption tests performed by dealerships; some marked passing via overfill, others showed 2+ quarts loss per 1,000 miles. Combustion chamber cleaning ($600–$800) attempted; did not resolve issue. Piston ring replacement and full engine replacement ($7,000–$8,000+) prescribed. One replaced engine failed within days.
Recalls/TSBs owners mention: Hyundai cited TSBs 20-01-002H, 20-01-004H, and 23-EM-008H (excessive oil consumption due to piston rings). Many warranty denials based on mileage (60,000–100,000 mile limits), second-owner status, or alleged 'maintenance neglect.' Corporate rejected goodwill requests despite oil-change records provided. Class-action lawsuit mentioned by multiple owners (Theta II GDI engines).
Cylinder Misfire & Low/Zero Compression
One or more cylinders lose compression or misfire, detected via check-engine light and confirmed by compression testing. Cylinder 3 and cylinder 2 failures most frequently reported.
When: Occurs across mileage range; some as early as 11,000 miles, others at 70,000–150,000 miles.
Symptoms owners cite: Check-engine light illuminates, often flashing (indicates misfire); Vehicle enters limp mode or runs sluggishly; Rough idle or stalling, especially at low RPM or stop lights; Engine studdering or hesitation during acceleration; Unburned fuel smell from exhaust
Codes mentioned: P0302 (Cylinder 2 Misfire), P0303 (Cylinder 3 Misfire), Knock-sensor overheat codes
Repairs/costs cited: Compression tests revealed 40% in affected cylinders vs. normal 180%. Spark plugs and coils replaced ($300) with minimal or no improvement. One owner cited piston damage in cylinder 3. Replacement engine prescribed in several cases at $7,000–$8,000+. One case documented blow-piston and cylinder #2 failure; catalytic converter replacement also required.
Recalls/TSBs owners mention: Hyundai declined warranty coverage in multiple cases, citing mileage limits or second-owner status. A few owners reported Hyundai Canada called to deny claims; one case mentioned extended warranty excludes piston failure. Some owners referenced recall 953 (knock-sensor detection system) but issues persisted post-recall.
Engine Fires & Smoke
Smoke and/or flames visible from engine compartment or under hood, typically during normal driving or while parked and refueling.
When: One case at 60,000 miles; another at 125,000 miles during refueling (parked); one at 11,000 miles; one in context of burning-oil complaints.
Symptoms owners cite: Smoke emitting from engine vents or compartment; Visible flames under hood; Burning oil or gasoline odor in cabin; Fire department called to extinguish flames
Repairs/costs cited: One vehicle destroyed by fire and towed away; cause not determined by time of complaint. Another fire extinguished by gas station attendant while refueling. Fire department responded to at least two incidents. Vehicle(s) not diagnosed or repaired by time of complaint.
Recalls/TSBs owners mention: Manufacturer notified in at least two fire cases. No remediation details provided in narratives.
Cracked Oil Pan (Drain-Plug Weld Area)
Hairline or visible crack in oil pan at or near the drain-plug weld spot, causing oil leaks without external impact damage.
When: One case reported crack present when car was new (11,000 miles); others at 49,000 and higher mileage.
Symptoms owners cite: Oil pooling or dripping onto ground beneath vehicle; No visible impact or dent on oil pan; Crack at spot-weld location near drain plug
Repairs/costs cited: Oil pan replacement required. Dealers sometimes blamed overtightening of drain plug despite no evidence of owner mishandling. Multiple owners note this is a reported common issue for this engine type.
Recalls/TSBs owners mention: One case: manufacturer contacted, case filed, no additional assistance provided. Others did not indicate manufacturer involvement or response.
Water Pump / Serpentine Belt Failure
Water pump malfunction on very low mileage (demo/new vehicle) caused belt to tear; replacement belt subsequently split/tore as well.
When: Occurred at approximately 5,000 miles (demo vehicle); replacement belt failure noted roughly 2 weeks later.
Symptoms owners cite: Engine overheating alert and hot temperature gauge reading; Visible splitting or tearing of serpentine belt; No explanation provided by dealer for failure on new vehicle
Repairs/costs cited: Water pump and belt replaced (initial repair ~7/29/19). Replacement belt visibly splitting by 8/16. Dealer denied any issue with new belt despite photographic evidence.
Recalls/TSBs owners mention: None indicated in narrative.
Engine Gasket Oil Leak
Faulty engine gasket allowing oil to seep from engine.
When: At 23,000 miles.
Symptoms owners cite: Oil leaking from engine
Repairs/costs cited: Engine gasket was replaced, resolving the failure.
Recalls/TSBs owners mention: Manufacturer not notified.
Timing Chain Failure
Timing chain failed, requiring engine replacement.
When: At approximately 220,000 miles (high mileage outlier).
Symptoms owners cite: Vehicle inadvertently revved and decelerated to 40 MPH while accelerator depressed at ~70 MPH; Check-engine light illuminated; Occasional need to add oil between changes
Repairs/costs cited: Timing chain failure diagnosed; engine replaced. Failure recurred post-repair.
Recalls/TSBs owners mention: Manufacturer notified and case number provided. Vehicle not repaired.
Synthesized from 68 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 11 most recent
The engine is burning oil around 1 quart every 700 miles. I check the car oil level around every 10 days. I have experienced when I didn't check the oil and the low oil engine light would come on in the instrument panel. Hyundai shows no recall for this 2019 Hyundai Sonata Limited edition. I believe that this type of incident occurred back around 2011 with Hyundai's models for that time
The part in question is the oil pan. An oil leak was identified at the place where I get my oil changed. The service center at the dealership informed me that there was a crack in the oil pan due to overtightening of the drain plug. I am not sure how they made that connection. The risk of this oil leak could lead to engine failure if oil levels drop below a certain level. There were no…
What component or system failed or malfunctioned, and is it available for inspection upon request? Since april 2025 i’ve been having low oil readings in my vehicle despite regular oil changes I took it into the dealer since my vehicle was still under warranty, which they stated only one part was under warranty. I had to pay $800 after this was replaced. I started having engine light come on. This…
My vehicle has an oil consumption problem. I put in 5 quarts of oil last week after changing the oil three weeks before this. I am down today December 19, 2025 2 1/2 quarts when I put in 5 quarts last Friday. Hyundai motor Corp. says I have to pay for the $90 oil change to do the oil consumption test then I have to go back 1000 miles later and pay $600 for an oil combustion cleaning and drive it…
The contact owns a 2019 Hyundai Sonata. The contact stated that the vehicle was experiencing excessive oil consumption. The vehicle was taken for an oil change, and the contact was informed that the vehicle required an oil change every 10 days. Additionally, the contact stated that the vehicle was taken to the dealer after driving 1,000 miles after an oil change, and the dealer informed the…
Hyundai replaced my engine under warranty due to their oil consumption in mid October. About 2 weeks later all warning lights came on and they said need new battery. They put in new battery in November. 15 miles after new battery a burning smell and smoke came from under hood with visible smoke. Took to dealer following day and no smoke. Got car back and next day it’s smoking and burning…
There is excessive oil consumption with the engine in my car. Hyundai says 1qt per 1000 miles is “acceptable” however this is not acceptable and can lead to catastrophic engine failure and oil slick on roadways if not caught in time. This is a know problem with Hyundai/Kia at this time. In many cases Hyundai/Kia owners are left with a “lemon” of a new car that is currently in warranty. Some have…
My oil light came on after driving it about 4700 miles from purchase date. I checked the oil and there was no oil on the dipstick. 200 miles and 2 days later the check engine light came on and put it into limp mode. It was about a half quart low. I was put at risk for having to go slow on a main highway to get back home. I took it to a local Hyundai dealership they did a diagnostic and bearing…
4500 miles after an oil change the oil drain plug fell out and oil leaked out resulting in an engine stalling. An oil warning light came on 7 minutes before the vehicle stalled on the highway.
I started the car and smoke came from the engine compartment I didnt think anything of it but the smoke keep getting worse . So I pulled over and open the hood to find fire come from on top of the Engine the flames got higher so I asked an local restaurant for an fire extinguisher I put it but know these cars this could of been an big problem if I had parked in the garage or park next to other…
Had engine trouble with your 2019 Hyundai Sonata?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2019 Hyundai Sonata?
It's a meaningful issue. 68 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Across the 16 complaints that reported odometer mileage, most engine failures cluster between 32,000 and 118,000 miles, with the median around 60,000. A quarter of owners report trouble before 32,000; a quarter make it past 118,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2019/Hyundai/Sonata.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.