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 Tucson engine problems
moderate Owners of the 2019 Hyundai Tucson have filed 133 NHTSA complaints about the engine, typically surfacing around 70,000 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
133
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2015 Tucson | 82 |
| 2016 Tucson | 236 |
| 2017 Tucson | 435 |
| 2018 Tucson | 157 |
| 2019 Tucson (this page) | 133 |
| 2020 Tucson | 55 |
| 2021 Tucson | 29 |
| 2022 Tucson | 55 |
| 2023 Tucson | 8 |
1crash
2fires
When does it fail?
Of the 133 engine complaints filed for the 2019 Hyundai Tucson, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 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 36% of every owner complaint on file for this vehicle — the dominant problem area across 10 categories tracked.
Owners have filed 133 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 ↗Certain 2019 – 2020 model year Santa Fe, 2017 – 2018 model year Santa Fe Sport, 2015 – 2019 model year Sonata, and 2018 – 2021 model year Tucson vehicles may exhibit elevated engine-out emissions. Hyundai is conducting a service campaign to update the Engine Control Module (ECM) Software for vehicles equipped with the (2.4 GDI) Theta II engine to improve engine combustion and fuel trim adaptations.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2019 Tucson engine failures fall into clear patterns. Most common is excessive oil burning—owners add 1–3 quarts between services with no external leaks visible. Dealership oil consumption tests often don't trigger coverage, and manufacturers claim it's "normal." When owners ignore low levels, check engine lights eventually appear and power drops to 25–30 mph on the highway—dangerous in 65–70 mph traffic.
Knock sensor failures repeat relentlessly. Owners get them replaced 2–5 times per vehicle, sometimes within months. Dealerships can't explain why, but one owner traced it to a worn serpentine belt the shop had missed. That suggests the sensor isn't the real problem—the engine's wear is.
Bearing failures are worst-case: connecting rod bearing collapse with no warning, just sudden knocking noise, then stalling. One owner's engine seized at 49,437 miles. Hyundai issued Campaign 966 (KSDS software update) to detect this in advance, but denies warranty to non-original owners or vehicles not yet in the campaign when purchased. Some owners report engine fires from excess oil reaching the catalytic converter.
Drain plugs back out even after mechanics confirm they're tight, dumping all oil instantly. One occurred 5,000+ miles after service. Hyundai issued a TSB on crush gasket replacement but still denies warranty, blaming the shop that did the oil change.
Through all of this, warranty denials are standard—manufacturers cite ownership status, maintenance records, or test results, leaving customers paying thousands for dealer rentals while engines sit weeks awaiting approval that never comes.
Same Hyundai Tucson engine reports on nearby years: 2016 · 2017 · 2018 · 2020 · 2021
Failure modes owners describe
Oil drain plug loosening/backing out
Oil drain plug becomes loose or backs out during or after oil changes, causing rapid oil loss and engine seizure. Occurs despite technician confirmation of tightening and without prior warning signs like residue or visible leakage.
When: Shortly after oil changes; one case at 5,000+ miles post-service; another at 50,000 miles
Symptoms owners cite: Blue smoke from exhaust; Engine and oil warning lights; Large amount of oil pooling under vehicle; Plug falls out when underbody shield removed for inspection
Repairs/costs cited: Engine seizure requiring replacement; oil plug/pan replacement recommended. TSB #[XXX] issued post-incident regarding crush gasket replacement and washer inspection.
Recalls/TSBs owners mention: TSB #[XXX] (issued after incidents) specifies crush gasket replacement and washer inspection; dealership denial of warranty citing third-party service (Walmart) responsibility
Knock sensor repeated failure
Knock sensor fails repeatedly, often replaced multiple times without resolving the underlying issue. Recurrence suggests underlying engine problem (such as worn serpentine belt, bearing wear, or internal misfiring) rather than knock sensor defect alone.
When: Throughout vehicle ownership; mileage ranges 44,990 to 56,712 in one case with 5+ occurrences over ~2 years
Symptoms owners cite: Check engine light flashing; Loss of power and vehicle slowdown; Limp mode activation; Inability to exceed 25-30 mph on highway at 70 mph speed
Codes mentioned: P1326
Repairs/costs cited: Knock sensor replaced 2–5 times per vehicle; software updates performed; one case resolved after worn serpentine belt replacement, suggesting belt wear was root cause; engine replacement recommended in some cases.
Recalls/TSBs owners mention: Recall (Campaign 966, NHTSA 21V727000) for knock sensor replacement and software updates; recall effectiveness questioned due to repeated failures even after multiple replacements
Excessive oil consumption (internal burning)
Engine burns oil internally at abnormally high rates without visible external leaks. Owners report needing to add 1–3 quarts of oil between 5,000-mile service intervals. Dealership oil consumption tests often inconclusive, with manufacturers denying coverage or offering partial cost-sharing.
When: Continuous throughout ownership; onset reported as early as first year; accelerates over time
Symptoms owners cite: Check engine light illumination; Oil level dropping rapidly between services; No visible oil leaks despite inspection; Excessive fuel smell in engine oil after combustion cleaning attempts; Intermittent low-oil warning (though some report light never comes on despite critically low levels)
Codes mentioned: P0420, P000A, P050A, P0017, P000B
Repairs/costs cited: Oil consumption tests (2–3 step process) often inconclusive or fail to trigger warranty; combustion chamber cleaning performed with mixed/negative results; no permanent repair achieved in most cases; owner maintenance at 2,000–3,000 mile intervals reported; extended warranties do not cover; costs escalate when internal engine damage results
Recalls/TSBs owners mention: Denial of warranty coverage citing oil consumption as 'within normal limits' or test failure; some offer 50% cost-sharing for partial repairs; case reassignments and lack of follow-up reported; manufacturers cite independently owned dealerships as unable to assist
Connecting rod bearing failure
Internal bearing wear or failure, often preceded by knocking noise, resulting in catastrophic engine damage and complete loss of function. Failure can occur without prior warning symptoms, leaving drivers stranded at highway speeds.
When: Ranges from 40,000 to 113,000 miles; some cases with minimal warning; one case at 49,437 miles
Symptoms owners cite: Engine knocking or banging noise; Loss of power (vehicle unable to exceed 25–30 mph); Check engine light and/or oil warning light; Engine stalling or failure to restart; Slapping noise before complete seizure
Codes mentioned: P1326
Repairs/costs cited: Engine replacement required; estimated cost $3,200–$8,000+ depending on labor and diagnostics. TSB and Class Action Settlement (E2 Class, Campaign 966, NHTSA 21V727000) exist for bearing defects but manufacturers use narrow denial criteria (e.g., software update not performed, non-original owner, timing of campaign relative to purchase).
Recalls/TSBs owners mention: Class Action Settlement (E2) and Service Campaign 966 (KSDS software update) designed to detect bearing wear; however, manufacturers deny coverage citing: vehicle not in scope at time of purchase, software update not performed (when owners not effectively notified), non-original owner status, maintenance record gaps, or distinction between 'rod bearing' vs. 'piston slap' to justify 50% cost-sharing or denial
Catalytic converter premature failure/clogging
Catalytic converter fails or clogs prematurely, often resulting from excessive oil consumption and unburned fuel reaching the converter. Multiple replacements required on same vehicle.
When: Between 29,933 and 113,000+ miles; some vehicles requiring replacement yearly or every 6 months
Symptoms owners cite: Check engine light illumination; Reduced power and sluggish acceleration; Vehicle unable to exceed 25–50 mph; Shuddering or jerking motion; Diagnostic codes indicating converter failure
Codes mentioned: P0420, P000A, P050A
Repairs/costs cited: Replacement cost $600+; one owner replaced converter 3 times over 5 years; multiple shops confirmed root cause is excessive oil consumption, not converter design; some dealers blamed clogging on owner's use of aftermarket/performance exhaust
Recalls/TSBs owners mention: Converter replacements may be covered under warranty depending on mileage and circumstances; however, manufacturers often refuse to address root cause (oil consumption) and deny coverage citing oil consumption test results or maintenance record gaps
Engine stalling/loss of power in traffic
Engine unexpectedly loses power, stalls, or enters limp mode while driving, often at highway speeds (35–70 mph), creating acute safety hazard. Vehicle unable to accelerate past 25–30 mph, stranding driver in traffic lanes.
When: Intermittent throughout ownership; up to 9+ occurrences in single vehicle; mileage ranges 35,000–132,000 miles
Symptoms owners cite: Check engine light flashing; Immediate loss of acceleration; Steering wheel vibration; Humming noise from engine; Vehicle enters limp mode and will not restart or restart requires multiple attempts; Gray or blue smoke from engine/underhood
Codes mentioned: P1326
Repairs/costs cited: No successful permanent repair identified across narratives; knock sensor replacement, software updates, and fuel injector cleaning attempted without resolution; engine replacement recommended but often denied by manufacturer
Recalls/TSBs owners mention: Repeated service visits with no diagnosis retained (codes cleared); dealerships unable to reproduce issue; manufacturer denies warranty based on various criteria; buyback offers made but rejected as insufficient; customers report communication breakdowns and lack of follow-up
Piston slap/internal engine noise and compression loss
Internal piston or bearing wear creating slapping noise and indicating compression loss or structural damage. Manufacturers distinguish 'piston slap' from 'rod bearing' failure to deny full warranty coverage, offering 50% cost-sharing instead.
When: Diagnosed post-failure at 100,000+ miles in some cases; one case pre-diagnosis at 48,042 miles
Symptoms owners cite: Engine knocking, slapping, or rattling noise; Loss of cylinder compression; Check engine light illumination; Power loss and limp mode; Misfire in specific cylinder
Codes mentioned: P1326
Repairs/costs cited: Engine replacement $3,200–$8,000; owners report diagnostician found missing piston piece; manufacturer offers 50% cost-sharing and denies full coverage by classifying as 'piston slap' rather than rod bearing defect
Recalls/TSBs owners mention: Warranty denials or 50% cost-sharing justified by distinction between 'piston slap' and 'rod bearing' failure; manufacturers claim piston slap falls outside extended warranty coverage despite being related to same defective engine family
Engine fire (oil-related)
Overheating catalytic converter and/or engine compartment fire caused by excess oil consumption and unburned fuel entering exhaust system. Vehicle fire resulting in complete engine destruction.
When: One confirmed case at 40,000 miles; another reported as risk scenario at higher mileage
Symptoms owners cite: Smoke coming from under hood and from rear of vehicle; Burning odor; Engine overheating; Smoke and flames under vehicle while driving (55 mph in reported case); Complete engine destruction
Repairs/costs cited: Vehicle total loss; fire department response required; no repair possible. One owner reports ongoing concern of engine fire due to unaddressed oil consumption and superheated catalytic converter.
Recalls/TSBs owners mention: Manufacturer declined responsibility in fire case, citing vehicle not at original owner (warranty limitation); oil consumption warnings not provided to owners despite alleged knowledge of risk
Software/sensor misdiagnosis and repeated service failures
Check engine light repeatedly illuminates with codes that dealerships cannot reproduce or resolve. Software updates and sensor replacements attempted without addressing root cause. Customers report dealership communication breakdowns, inability to diagnose, and repeated failures after service.
When: Intermittent from first year of ownership through multiple years; December 2022 to January 2026 in one case spanning 40+ months
Symptoms owners cite: Check engine light on/flashing intermittently or repeatedly after service; Codes cleared at dealership but reappear days/weeks later; Unable to diagnose or reproduce problem; Software updates and sensor replacements fail to resolve
Codes mentioned: EVAP leak code, P1326, Misfire codes
Repairs/costs cited: Multiple visits (4–9+) to dealership without permanent resolution; software updates attempted; sensors replaced; extended diagnostic fees ($185–$250) charged to customers; no effective repair achieved
Recalls/TSBs owners mention: Dealership unable or unwilling to investigate root cause; manufacturer case reassignments and lack of follow-up; some cases offered buyback or partial settlement; communication failures documented (no returned calls/texts, 3-month waits without updates)
Underbody/drain pan defect (loose drain plug backing out)
Drain plug backing out due to defective threads, gasket design, or pan defect. Occurs even when mechanic confirms tightening. No prior warning signs.
When: During or shortly after oil changes; one case with 5,000+ miles post-service
Symptoms owners cite: Sudden loss of all engine oil; Blue smoke from exhaust; Engine and oil warning lights; Large puddle of oil under vehicle; Plug found loose on underbody shield during inspection
Repairs/costs cited: TSB #[XXX] issued to replace one-time use crush-type gasket and verify no old washer stuck in opening; engine requires replacement due to seizure; alleged design/manufacturing defect in plug or pan
Recalls/TSBs owners mention: TSB #[XXX] issued post-incidents; warranty claims denied, citing responsibility of third-party service provider (Walmart); TSB notes that engine damage from improper gasket installation may be subject to warranty chargeback—implying manufacturer knew of issue before some customer failures
Synthesized from 133 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 9 most recent
The contact owns a 2019 Hyundai Tucson. The contact stated that while driving on the highway at 70 MPH when the vehicle acceleration speed was reduced to 40 MPH independently. The check engine warning light had illuminated. The vehicle was taken to a local dealer where it was diagnosed that the gasket fuel pump, camshaft, timing chain, timing chain sensor, and intake cam were faulty and would…
Hello, my 2019 Hyundai Tuscan I have owned for 3 years-4 years. Unfortunately it is a GDI Motor, it uses oil so bad, even though I do change the oil every 3,000 miles, and do every maintenance on the vehicle that is told to me done, ever time I change the oil it is low, even though I top it off through out the 3,000 miles. I have no leaks at all and it is just evaporating, I do not think this is…
I have been having a problem with the car where the car has a cold start no matter if its summer or winter in california. When I push the start button the car struggles to start and then does start after 2-3 seconds. This problem have been since there when the car was just 500miles on it and the issue exists as of today. It went to the dealership twice and came back saying there is no problem. I…
My 2019 Hyundai Tucson previously required an engine replacement due to a known defect. After the engine replacement, the check engine light remained on. Recently, the check engine light began flashing, and the vehicle was towed to the dealership. I was informed the vehicle has a radiator/cooling system failure. Given the history of engine defects and warning lights, I am concerned about vehicle…
I am submitting this complaint regarding excessive and abnormal oil consumption in my 2019 Hyundai Tucson. Despite regular maintenance and oil changes performed according to manufacturer recommendations, my vehicle consumes oil at an excessive rate, requiring frequent oil top-offs between oil change intervals. I have experienced low oil levels with little to no warning, which poses a serious…
The contact owns a 2019 Hyundai Tucson. The contact stated that while her husband was driving at an undisclosed speed, several unknown warning lights illuminated. The vehicle was taken to an independent mechanic and diagnosed with engine failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 86,000.
Oil component failure causing extreme heating within the engine and catalytic converter which poses risk for engine fire. This oil consumption issue was addressed by the dealership who ran a test to see how much oil was consumed. The test results showed that the vehicle was burning oil at a high rate and would ultimately result in engine failure. The low-oil light has never come on indicating…
My 2019 Hyundai Tucson, VIN [XXX] , has developed engine knocking, which may indicate internal engine failure. A mechanic has suggested a possible loss of cylinder compression, though the exact cause has not been confirmed. Hyundai vehicles from similar model years have experienced engine failures related to bearing wear and metal debris, leading to stalling, loss of power, and complete engine…
My 2019 Hyundai Tucson, VIN [XXX] , has developed engine knocking, which may indicate internal engine failure. A mechanic has suggested a possible loss of cylinder compression, though the exact cause has not been confirmed. Hyundai vehicles from similar model years have experienced engine failures related to bearing wear and metal debris, leading to stalling, loss of power, and complete engine…
Had engine trouble with your 2019 Hyundai Tucson?
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 Tucson?
It's a documented issue but not catastrophic. 133 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 25 complaints that reported odometer mileage, most engine failures cluster between 50,000 and 89,000 miles, with the median around 70,000. A quarter of owners report trouble before 50,000; a quarter make it past 89,000. 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/Tucson.
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.