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 ↗2016 Kia Sorento engine problems
moderate Owners of the 2016 Kia Sorento have filed 548 NHTSA complaints about the engine, typically surfacing around 85,000 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
548
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2012 Sorento | 344 |
| 2013 Sorento | 385 |
| 2014 Sorento | 278 |
| 2015 Sorento | 284 |
| 2016 Sorento (this page) | 548 |
| 2017 Sorento | 307 |
| 2018 Sorento | 81 |
| 2019 Sorento | 117 |
| 2020 Sorento | 48 |
3crashes
20fires
1injury
When does it fail?
Of the 548 engine complaints filed for the 2016 Kia Sorento, here's the actual mileage breakdown — failures cluster heaviest at 150,000+ 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
Of the 18 model years of Kia Sorento we track for engine problems, this one carries the most owner complaints on file — 548.
Engine accounts for 44% of every owner complaint on file for this vehicle — the dominant problem area across 12 categories tracked.
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: WARRANTY EXTENSION CAMPAIGN: OIL PRESSURE SWITCH (OPS) REPLACEMENT (WTY026 REVISION 2) - 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 regarding the replacement of the Oil Pressure Switch associated with the ‘Warranty Extension Program’ (WTY026) on some 2014-2018MY vehicles listed in the table below, for repairs that may be necessary to address an Oil Pressure Switch leak in the eligible vehicles listed below from 10 years/100,000 miles to 15 years/150,000 miles, whichever comes first, starting from the date the vehicle was
full bulletin at NHTSA ↗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 ↗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 describe a consistent failure pattern in 2016 Kia Sorento engines: head bolts back out of the aluminum engine block, head gasket seals fail, coolant leaks into cylinders, and the engine overheats—all without warning lights. The problem strikes between 50,000 and 125,000 miles, often right when the warranty expires or shortly after a second-owner purchase. Dealership service managers confirm this is "a known manufacturing defect" and report replacing multiple engines per week.
Excessive oil consumption runs parallel to these failures. Owners report burning 1–3 quarts every 500–1,500 miles with no leaks and no warning lamp. Kia's suggested fixes—intake cleaning, combustion chamber service, spark plug replacement—don't resolve the root cause. Eventually the engine knocks, misfires in specific cylinders, fouls plugs with oil, or seizes entirely.
Many owners report complete engine failure on highway while driving, with zero warning lights illuminated beforehand. One owner's engine shut off in a busy intersection; another lost power crossing three lanes at 70 mph with semi-trucks passing. The oil pressure sensor defect prevents lamp activation even when oil is bone dry.
Warranty coverage is spotty. Extended coverage issued in late 2023 for some vehicles, but second owners are routinely denied (limited to 60,000 miles instead of 100,000). Kia corporate refuses to call these failures a "recall," citing the narrow applicability of prior recalls, and denies claims based on missing knock sensor upgrades that original owners never completed or documented. Engine replacement costs $10,000–$18,000, and dealerships often have no engines in stock.
Same Kia Sorento engine reports on nearby years: 2014 · 2015 · 2017 · 2018 · 2019
Failure modes owners describe
Head Gasket and Head Bolt Failure (3.3L V6 GDI)
Head bolts back out of the aluminum engine block, causing head gasket failure and loss of coolant seal. Threads in the aluminum block strip or pull away from the dissimilar-metal bolts, reducing clamp load on the gasket. Coolant leaks into cylinders and overheating occurs without warning. Owners report dealerships noting this as a known manufacturing defect.
When: Reported between 50,000 and 125,000 miles; often occurs near end of warranty period or shortly after second-owner purchase.
Symptoms owners cite: Engine overheating without warning lights; Coolant smell and white smoke from exhaust; Loss of power while driving; Coolant level dropping or empty reservoir; Bubbling in coolant reservoir; Engine knocking sound; Temperature gauge spiking to 'H' mark
Codes mentioned: P0300 (random misfire), P1326 (knock sensor code)
Repairs/costs cited: Kia dealerships recommend full engine replacement; cost ranges $10,000–$18,000. New engines unavailable in many cases due to refurbishment backlog. Attempted repairs (bolt retapping, reboring) offered without warranty. Second-owner vehicles ineligible for original 100K-mile powertrain warranty.
Recalls/TSBs owners mention: Extended warranty to 100,000 miles for certain 2016 Sorento GDI engines (issued in December 2023 for some owners), though coverage denials cited due to missing recall completion or lack of formal diagnostic codes. Kia has not issued recall for 3.3L engines despite acknowledged manufacturing defect.
Excessive Oil Consumption
Engine burns oil at abnormally high rates with no visible leaks. Oil pressure sensor defect and/or internal engine wear (piston rings, valve guides) allow oil to enter combustion chambers and be consumed. Condition worsens over time and is exacerbated by prolonged low-oil operation.
When: Begins as early as 4,000 miles after purchase in some cases; accelerates after 50,000–80,000 miles. Commonly identified when oil light flickers or owner monitors dipstick.
Symptoms owners cite: Oil light flickering intermittently; Oil level dropping 1–3+ quarts between changes; No visible leaks underneath vehicle; Check engine light appearing; Engine running rough or misfiring (due to oil fouling spark plugs); No warning lamps until critical failure imminent
Codes mentioned: P0301–P0306 (cylinder misfire codes), P0304, P0305, P0306 (specific cylinder misfire)
Repairs/costs cited: Dealerships initially recommend intake manifold cleaning, valve cover gasket replacement, combustion chamber cleaning ($500 service), or spark plug/coil replacement ($300+). None resolve root cause. End result: full engine replacement ($6,500–$10,000) once condition becomes critical and engine knocking begins. Oil pressure sensor replacement (part cost ~$14, repair ~$400) rarely performed as prophylactic measure.
Recalls/TSBs owners mention: Kia has issued 'extended coverage' and software updates (KSDS SC260 knock sensor software) but refuses to acknowledge problem as systemic defect or recall. Service advisors tell owners 'to drive the car until the motor ceases.' Warranty claims routinely denied post-expiration; some owners report being advised to complete 1,000-mile oil consumption tests but results ignored.
Connecting Rod Bearing Failure
Rod bearings wear and fail due to lack of lubrication caused by excessive oil consumption. Bearing wear reduces oil pressure, leading to catastrophic engine seizure. Occurs without warning and correlates with prior history of oil consumption issues.
When: Typically occurs after 100,000 miles or after prolonged oil consumption problems; can happen suddenly with no prior warning.
Symptoms owners cite: Engine knocking sound (often described as 'rod knock'); Loss of power and acceleration; Oil pressure light illuminating; Check engine light; Engine stalling without warning; Complete engine seizure
Codes mentioned: P0300 (random misfire), P1326 (knock sensor)
Repairs/costs cited: Requires full engine replacement; bearings not separately rebuilt. Cost $10,000–$18,000 for new/remanufactured engine plus labor and towing. Some warranty programs (e.g., 'My Warranty Forever') explicitly deny coverage or demand photos of failed components before labor is approved.
Recalls/TSBs owners mention: Kia has extended rod-bearing warranty coverage to 100,000 miles for certain model years but denies coverage post-warranty expiration. Many owners excluded because warranty expired before failure or because they are second/third owners. Some owners claim Kia told them verbally that engine replacement would be covered only 'after bearing fails' but refused to document such assurance in writing.
Engine Block Cracking and Warping
Aluminum engine blocks and cylinder heads warp due to overheating and thermal stress, or crack adjacent to connecting rods. Threads in aluminum block become damaged and unusable; machine shop cannot mill and retap blocks to acceptable tolerances. Heat and combustion pressure cause catastrophic structural failure.
When: Occurs concurrently with overheating events or after prolonged oil starvation; mileage range 50,000–145,000 miles.
Symptoms owners cite: Violent engine shaking and vibrating; Loud banging or knocking noise from engine; Engine losing power suddenly; Smoke and heat visible from engine bay; Engine stalling without restart capability; Oil pressure, check engine, and battery warning lights
Repairs/costs cited: Block cracking is irreversible; full engine replacement mandatory. Costs $10,000–$18,000. Machine shops report inability to repair due to severity of warping and crack propagation. Parts sent out for inspection show impossible-to-repair damage.
Recalls/TSBs owners mention: Kia denies coverage citing warranty expiration or vehicle mileage exceedance. Prior recall (RQ17-003 NHTSA Recall No. 17V-224) applied only to 2.0 and 2.4 liter GDI engines; 3.3L engines excluded despite being produced in same facility and exhibiting identical failure modes.
Knock Sensor Upgrade Campaign Non-Completion
Kia issued a knock sensor upgrade campaign in 2018 targeting the first owner of record. When vehicles change ownership, second owners do not receive recall notice and are unaware of the campaign. Engine subsequently fails, and Kia denies warranty coverage claiming the knock sensor upgrade was not performed.
When: Failures occur years after purchase by second owner, well after the campaign window closed and notice was not reissued.
Symptoms owners cite: Engine knocking; Loss of power on highway; No warning lights until failure imminent; Complete engine seizure
Codes mentioned: P1326 (knock sensor)
Repairs/costs cited: Full engine replacement required; cost $10,000+. Owner forced to pay out-of-pocket despite being unaware of prior campaign due to vehicle ownership transfer.
Recalls/TSBs owners mention: Kia denies warranty claims on grounds that knock sensor upgrade campaign was not completed. Campaign notice was sent to original owner only; second owner never received notice and had no opportunity to complete upgrade. Kia refuses responsibility for lack of notice transfer to subsequent owners.
High-Pressure Fuel Pump Failure
High-pressure fuel pump stops supplying adequate fuel to the engine, causing stalling, loss of acceleration, and inability to restart. Condition appears shortly after water pump replacement or following engine stalling events, suggesting potential defect or improper repair sequencing.
When: Occurs early in ownership (around 30,000 miles in one case) or shortly after other repairs performed.
Symptoms owners cite: Engine stalling during acceleration or on highway; Check engine light illuminated; Loss of power and inability to accelerate; Vehicle will not start or restart; No onboard diagnostic detection (despite failure occurring)
Repairs/costs cited: Fuel pump replacement cost $1,350 reported in one case. Recurring issue: same pump fails again within days/weeks despite replacement, suggesting defective part source or underlying fuel system issue.
Recalls/TSBs owners mention: Kia dealership (Kia of Johnson City, TN) replaced pump twice; blamed gas in oil on second occurrence. Refused refund or buyback despite multiple failures and loss of power on interstate highway.
Cylinder Head Gasket Leakage (Non-Bolt Failure)
Gasket material deteriorates or fails independent of bolt backing-out, allowing coolant to seep into cylinders. Symptom pattern similar to bolt failure but root cause is gasket degradation or improper sealing surface.
When: Can occur from 40,000 miles onward, often after extended warranty period.
Symptoms owners cite: Coolant smell; Overheating without warning; Loss of coolant without visible leaks; White smoke from exhaust; Cylinder misfires; No warning lights until failure critical
Codes mentioned: P0300 (random misfire)
Repairs/costs cited: Gasket replacement alone ($400–$500) often fails to resolve problem; mechanics recommend full engine replacement. Some dealerships replace gasket but do not warrant work due to aluminum head material concerns.
Recalls/TSBs owners mention: Some covered under extended warranty issued in late 2023; others denied if warranty expired or second-owner status applies. Dealerships inconsistent in acknowledging defect versus blaming owner maintenance.
Cylinder Misfire and Carbon Buildup
Fuel injectors fail, spark plugs foul with oil, or carbon accumulates in combustion chambers due to oil intrusion. Multiple cylinders misfire; check engine light flashes. Issue may originate from excessive oil consumption, improper fuel-to-air ratio, or defective fuel injectors.
When: Appears intermittently, then becomes chronic; often after 75,000–120,000 miles.
Symptoms owners cite: Check engine light flashing (critical); Engine running rough or sluggish; Acceleration hesitation or failure; Rough idle; Multiple spark plugs fouled with oil; Fuel injector deposits (suspected)
Codes mentioned: P0301 (random misfire), P0304, P0305, P0306 (specific cylinder misfire), P0200 (injector circuit)
Repairs/costs cited: Shops replace spark plugs, coils, fuel injectors, and perform intake manifold cleaning ($500) without resolution. Root cause (oil consumption, bearing wear, head gasket leakage) not addressed. Continuous repair cycle costs owners $300–$800+ in incremental repairs before catastrophic failure.
Recalls/TSBs owners mention: Kia claims carbon buildup is not linked to oil consumption; denies good-faith repair despite service manager at dealership confirming the two are related. Warranty coverage denied for misfire-related work.
Limp Mode and Stalling Events
Vehicle enters 'limp mode' (reduced power, ~15 mph max) or stalls suddenly on highway or in traffic without warning, creating immediate safety hazard. Engine may restart and run briefly, then fail again. Associated with misfires, knock sensor issues, or transmission control module reacting to engine problems.
When: Unpredictable; occurs during normal highway driving or in heavy traffic. No warning phase.
Symptoms owners cite: Sudden loss of power while driving; Engine stalling mid-acceleration or mid-intersection; Vehicle limping at 15 mph (limp mode); Check engine light illuminating; Engine restarting and stalling repeatedly; No prior warning lights or symptoms
Codes mentioned: P1326 (knock sensor), P0300 (random misfire)
Repairs/costs cited: Knock sensor replacement ($200–$300) performed but does not prevent recurrence in many cases. Deeper engine issues (bearing wear, misfire) not resolved. Vehicle remains unsafe for highway use.
Recalls/TSBs owners mention: Kia dealerships replace knock sensor and declare vehicle 'good to go,' but failures recur. Extended warranty and recalls do not universally cover all vehicles, and diagnostic codes are sometimes absent despite failure occurring.
Oil Pressure Sensor Defect
Oil pressure sensor fails to illuminate warning lamp despite critically low oil levels, leaving driver unaware of dangerous condition. Sensor design or wiring fault prevents alarm from activating even when oil is bone dry or nearly gone.
When: Defect can exist from early ownership (first oil change onward) but often not detected until catastrophic engine failure occurs.
Symptoms owners cite: No oil warning light despite very low or absent oil on dipstick; Engine operating undetected with critically low oil; No thermal or pressure alerts before sudden failure; Engine seizing with no prior lamp illumination
Repairs/costs cited: Sensor replacement cost approximately $14 in parts; labor ranges $300–$400 depending on shop. Rarely replaced proactively; typically discovered after engine failure. Proper functioning could have prevented catastrophic failure.
Recalls/TSBs owners mention: No recall issued for this defect despite known issue described on NHTSA website and YouTube forums for over 7 years. Kia has not addressed as systemic recall.
Synthesized from 548 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 6 most recent
We have to constant add oil to the engine in between our 3000 mile oil changes, at least a quart or more. There are no oil leaks anywhere on the engine. The engine makes a loud "ticking" noise and doesn't have the power. The transmission also has issues shifting from 1st to 2nd gear. We have even noticed from time to time a smell of gasoline from what seems to be coming from under the vehicle,…
Driving on highway, vehicle lost power. Ultimate diagnosed as a seized engine. Car was towed to our mechanic. After contacting Kia, they had us tow it to a local Kia dealer. After they diagnosed the same seized engine, they said they would not pay for repair, despite their being a class action suit settled by them. Car was brought back to our mechanic and a used engine was put in.
I was driving on the Thruway and suddenly my check engine light came on and a large plume of black smoke came from the exhaust. The car was misfiring badly. I nursed it home and the next day took it to my mechanic, hoping it was a coil or plug. I had almost zero compression in cylinder #2. I then took vehicle to his engine repair shop. The owner told me the next day that I needed a new engine. I…
The contact owns a 2016 Kia Sorento. The contact stated while driving 20 MPH and making a left turn, the vehicle lost power. The accelerator pedal was depressed down to the floorboard; however, the vehicle failed to respond. The contact drove the vehicle for a mile to the workplace. The vehicle was taken to an independent mechanic where it was diagnosed and determined that the head gasket and…
Vehicle check engine light came on, vehicle lost power, sputtered and died. Will not run. Towed to dealer.
2016 Kia sorento. Consumer writes in regards to vehicle will not shift properly and failed to accelerate over 30 MPH. *smd the manifold assembly intake was replaced three times. *jb
Had engine trouble with your 2016 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 2016 Kia Sorento?
It's a documented issue but not catastrophic. 548 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 151 complaints that reported odometer mileage, most engine failures cluster between 65,218 and 119,000 miles, with the median around 85,000. A quarter of owners report trouble before 65,218; a quarter make it past 119,000. 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/2016/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.