VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSIONS: ECM LOGIC IMPROVEMENT (SC340 REVISION 5) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to upgrade the Electronic Control Module ‘ECM’ system software for certain 2016-2020MY Optima, 2016-2020MY Sorento, 2017-2022MY Sportage vehicles equipped with 2.4L Theta II engines listed in the table below. Kia has become aware that certain 2016-2022MY vehicles equipped with 2.4L Theta II engines may have engine calibrations that were not optimized for emissions standards under certain specific co
full bulletin at NHTSA ↗2020 Kia Sorento engine problems
severe Owners of the 2020 Kia Sorento have filed 48 NHTSA complaints about the engine 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 →
Complaints
48
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2016 Sorento | 548 |
| 2017 Sorento | 307 |
| 2018 Sorento | 81 |
| 2019 Sorento | 117 |
| 2020 Sorento (this page) | 48 |
| 2022 Sorento | 20 |
| 2023 Sorento | 10 |
| 2024 Sorento | 3 |
1crash
3fires
2injuries
When does it fail?
Of the 48 engine complaints filed for the 2020 Kia Sorento, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 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 37% of every owner complaint on file for this vehicle — the dominant problem area across 7 categories tracked.
Owners have filed 48 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.
TECHNICAL SERVICE BULLETIN: VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSION SECM LOGIC IMPROVEMENT (SC340 REV 4) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to upgrade the Electronic Control Module ‘ECM’ system software for certain 2016-2022MY vehicles equipped with 2.4L Theta II engines listed in the table below. Kia has become aware that certain 2016-2022MY vehicles equipped with 2.4L Theta II engines may have engine calibrations that were not optimized for emissions standards under certain specific conditions. These calibrations
full bulletin at NHTSA ↗VOLUNTARY EMISSIONS SERVICE CAMPAIGN: OWNER NOTIFICATION (SC340 FLIGHT 103 / UM) - This document is the owner notification advising that Kia is conducting a Voluntary Emissions Service Campaign to improve the emissions software logic in the Electronic Control Module (ECM) for certain 2016-2020 MY Sorento vehicles equipped with 2.4L Gas Direct Injection (GDI) engines to ensure compliance with emissions regulations.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSIONS ECM LOGIC IMPROVEMENT (SC340) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to upgrade the Electronic Control Module ‘ECM’ system software for certain 2016-2022MY vehicles equipped with 2.4L Theta II engines listed in the table below. Kia has become aware that certain 2016-2022MY vehicles equipped with 2.4L Theta II engines may have engine calibrations that were not optimized for emissions standards under certain specific conditions. These calibrations may c
full bulletin at NHTSA ↗VOLUNTARY EMISSIONS SERVICE CAMPAIGN: OWNER NOTIFICATION (SC340 FLIGHT 101 / UM) - This document is the owner notification advising that Kia is conducting a Voluntary Emissions Service Campaign to improve the emissions software logic in the Electronic Control Module (ECM) for certain 2016-2020 MY Sorento vehicles equipped with 2.4L Gas Direct Injection (GDI) engines to ensure compliance with emissions regulations.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2020 Kia Sorentos describe a cascade of engine problems that start with excessive oil consumption, typically between 80,000 and 100,000 miles. The consumption rate is extreme—1 to 2.5 quarts per 1,000 miles—forcing weekly or bi-weekly top-ups despite no visible leaks at the pan or drain plug. Dealerships acknowledge the pattern, with one tech telling a complaint that he sees this "all the time" and advising owners to switch to 3,000-mile oil change intervals.
From excessive consumption, the failures escalate: cylinder wall scoring surfaces during dealer inspections, spark plugs foul with oil residue, misfire codes (P0304 and others) appear, and the engine stalls without warning—sometimes on highways at speed. Owners report a loud knocking or rattling noise just before the engine seizes or loses all power, occasionally accompanied by white smoke or actual fire. Some vehicles fail to restart after a stall; others must be towed immediately. Failures occur as early as 58,000 miles but cluster heavily between 100,000 and 150,000 miles.
Engine replacement costs around $5,000–$11,000 out-of-pocket. Kia's typical response is refusal: the oil consumption test fails, but warranty coverage and recall eligibility are routinely denied on grounds of mileage (over 100,000), prior ownership status, or outright exclusion from the settlement class action. Owners cite a pattern of manufacturer deflection and procedural roadblocks.
Same Kia Sorento engine reports on nearby years: 2017 · 2018 · 2019 · 2022
Failure modes owners describe
Excessive Oil Consumption
Engine burns 1–2.5 quarts of oil per 1,000 miles, with no visible leaks, forcing frequent top-ups. Oil level drops from full to low or empty within days to weeks of driving. Occurs despite proper maintenance and no mechanical damage visible at first inspection.
When: Typically 80,000–100,000 miles; some as early as 36,000 and 37,000 miles; continues until engine failure
Symptoms owners cite: Rapid oil level drop between services; No visible leak at pan or drain plug; Need to add oil weekly or bi-weekly; Owner must perform frequent dipstick checks; Smell of burning oil inside cabin
Repairs/costs cited: Dealers acknowledge the pattern but often recommend higher service frequency (3,000-mile intervals) rather than repair. Some perform oil consumption tests; others refuse. No repair is offered; only monitoring until engine failure occurs.
Recalls/TSBs owners mention: Kia acknowledges issue in some cases via oil consumption testing but denies warranty coverage and recalls on grounds of mileage over 100,000 miles, prior ownership, or non-inclusion in settlement. Extended warranty companies (e.g., JM&A) deny claims citing 'lack of oil' as user error.
Cylinder Wall Scoring and Internal Wear
Progressive internal engine deterioration with visible cylinder wall scoring detected during dealer inspections. Metal shavings appear in oil pan. Indicates bearing or ring wear progressing toward seizure.
When: Mid-mileage during oil consumption phase; one case documented at 80,000 miles
Symptoms owners cite: Visible scoring on cylinder walls per dealer inspection; Metal shavings in oil pan; Oil fouling of spark plugs
Repairs/costs cited: Scored cylinders require full engine replacement; no repair available. Owners report dealership refusal to authorize replacement until 'catastrophic breakdown' occurs.
Recalls/TSBs owners mention: Manufacturer refuses warranty replacement despite confirmed cylinder damage, citing policy requiring complete mechanical failure before authorization.
Cylinder Misfire and Check Engine Light
One or more cylinders misfire, triggering check engine light and drivability issues. Commonly codes P0304 (Cylinder 4 misfire) documented in multiple complaints. Spark plug and coil pack replacement does not resolve the issue; actual engine damage is root cause.
When: 80,000–130,000 miles
Symptoms owners cite: Check engine light (flashing or steady); Cylinder 4 misfire code P0304; Vehicle sputtering while driving; Difficulty accelerating, sluggish response; Harder to start each time; Oil-fouled spark plugs
Codes mentioned: P0304
Repairs/costs cited: Owners replaced spark plugs and coil packs; misfire persisted. Mechanics diagnosed failing engine requiring full replacement. One owner spent on fuel injector diagnosis (which Kia blamed) before addressing underlying oil starvation.
Recalls/TSBs owners mention: Kia denies coverage, citing mileage over warranty thresholds. Some dealers misdiagnose as fuel injector issue to avoid warranty obligation.
Engine Seizure and Complete Failure
Engine suddenly seizes, loses all power, or ceases to respond. Loud knocking, rattling, or pop sound immediately precedes failure. Vehicle stalls and will not restart. Occurs with no prior warning lights in some cases, or only after misfire has begun.
When: 58,000–151,000 miles; cluster at 100,000–150,000 miles
Symptoms owners cite: Sudden loud knocking or rattling noise from engine; Muffled pop or explosion sound; Engine stalling without warning, sometimes at highway speeds; Vehicle will not restart after stall; Loss of power while driving; Shaking or vibration before stall; No oil on dipstick at time of failure
Repairs/costs cited: Failure diagnosis includes connecting rod bearing failure (holes in engine block), complete oil starvation, and seizure. Tow required. Engine replacement only option; cost $5,000–$11,000 out-of-pocket in all cases. One case documented via insurance inspection after vehicle fire.
Recalls/TSBs owners mention: Manufacturer provides no assistance. Denies warranty or recall coverage. One case notes dealer stated vehicle must continue operation until 'catastrophic breakdown' before replacement authorized.
Engine Fire
Engine catches fire while driving or immediately after vehicle stops. White smoke from under hood or engine compartment precedes fire in some cases. Fire occurs with no prior indication or warning light in at least one case; vehicle completely engulfed within minutes.
When: 58,000–150,000 miles
Symptoms owners cite: White smoke from under hood while driving; Fire igniting in engine compartment; Sudden loss of power before or concurrent with fire; Engine stalling before fire starts
Repairs/costs cited: Vehicle fire-damaged, towed to insurance company. One case: NHTSA manufacturer inspector confirmed origin of fire was engine failure. One case: vehicle completely consumed by fire; occupants safely evacuated.
Recalls/TSBs owners mention: Manufacturer notified in one case; inspector confirmed fire origin was engine failure but provided no other information. No warranty or repair response documented.
Oil Pan Drain Plug Failure
Oil drain plug works loose and falls out during operation, causing catastrophic oil loss and immediate engine failure. Owner found plug in splash shield after the fact.
When: Documented at unknown mileage; loss of oil on highway
Symptoms owners cite: No warning of leak before plug fell out; Sudden cloud of black smoke from vehicle; Complete loss of engine oil; Engine seizing on highway due to starvation
Repairs/costs cited: Engine replacement required; cost $11,000. Plug found in splash shield. Problem documented to NHTSA and other maintenance organizations.
Recalls/TSBs owners mention: No manufacturer response documented; issue reported to NHTSA.
Radiator Failure and Overheating
Engine overheats beyond radiator capacity, causing radiator to crack and fail. Occurs in one complaint alongside other engine issues.
When: Timing not specified
Symptoms owners cite: Engine overheating; Radiator cracking and rupture
Repairs/costs cited: Radiator replacement required; no cost cited.
General Engine Oil Leak
Oil leaking from engine; specific source not identified in complaint but dealership indicates engine replacement needed. Appears to be separate from or in addition to consumption issues.
When: Timing not specified; vehicle only 6 years old
Symptoms owners cite: Oil leak from engine
Repairs/costs cited: Dealership advised engine replacement
Synthesized from 48 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 6 most recent
I was informed at routine maintenance that engine was burning oil. This was an issue since I purchased vehicle at 16k miles. Shortly after 80,000 engine spontaneous started knocking. I had it towed to the dealership that confirmed it was a spontaneous engine failure.
The contact owns a 2020 Kia Sorento. The contact stated that while the vehicle was parked, the contact noticed a small oil leak on the ground underneath the vehicle. The contact checked the oil level and added a quart of oil to the engine. The vehicle was driven approximately 50 miles. The contact parked the vehicle and checked the oil level again. They noticed that the oil level was low and…
On 11/19/2024 I was driving when my Kia begin to sputter and lose power, and the check engine light came on. I was on an interstate so I exited and pulled over, after paying 400.00 in tow fees it was determined my engine had failed with only 126,291 miles. I never had any indication of problems with my engine it happened in the blink of an eye
I have noticed at around 36,000 miles excessive oil consumption and knocking sound in the engine.I know the have this problem with older models, but you get the push around from dealership and Kia corporate. Thanks
The contact owns a 2020 Kia Sorento. The contact stated that while driving approximately 53- 55 MPH, the contact suddenly noticed that their surrounding drivers were honking for her attention. Eventually, another nearby driver notified the contact by pointing down and yelling out "fire". The vehicle then stalled and the contact was able to use its momentum to coast to the side of the road where…
My car is burning excessive amounts of oil with no leak
Had engine trouble with your 2020 Kia Sorento?
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 2020 Kia Sorento?
It's a meaningful issue. 48 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?
Based on the 48 complaints filed, engine issues most often appear around 109,670 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
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/2020/Kia/Sorento.
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.