Hyundai Theta II Engine: years, specs & known problems

By CarWhere Research · Updated

Theta II is the Hyundai–Kia inline-four family behind the 2.4L GDI and 2.0L turbo GDI engines in 2011–2019 Sonata, Santa Fe Sport, Tucson, Optima, Sorento and Sportage models. Its defining issue is connecting-rod bearing wear, handled through recalls, the KSDS software update and a lifetime short-block warranty under a 2021 class settlement.

Theta II covers several US engines: the 2.4L gasoline direct-injection (GDI) four, the 2.0L turbocharged GDI four, and an older 2.4L multi-point-injection (MPI) four used in 2010–2016 models, including the first Sonata Hybrid and Optima Hybrid. EPA listings show the direct-injected 2.4L in the Sonata from 2011 and the 2.0T from 2011, with Kia using the same displacements in the Optima, Sorento and Sportage.

The engines are best known for connecting-rod bearing wear. Hyundai recalled 470,000 2011–2012 Sonatas in September 2015 (15V568), then 572,000 2013–2014 Sonatas and Santa Fe Sports in March 2017 (17V226), the same day Kia recalled 618,160 Optima, Sorento and Sportage models (17V224). Follow-up recalls fixed fuel-pipe and fuel-hose leaks. Both brands also rolled out the Knock Sensor Detection System (KSDS), software that monitors the engine for signs of bearing wear and, if it finds them, turns on the check-engine light and puts the car in a temporary engine protection mode. The 2021 Engine I settlement (In re: Hyundai and Kia Engine Litigation, C.D. Cal.) turned the powertrain warranty on 3,956,568 class vehicles into a lifetime short-block warranty for owners who installed KSDS. A second settlement (Engine II, 2024) covers the 2.4L MPI and other engines with a 15-year/150,000-mile warranty.

Theta II (2.4L and 2.0T) at a glance

Hyundai/Kia Theta II inline-four: 2.4L GDI, 2.0L turbo GDI and 2.4L MPI (US 2010–2022): model years, fuel and peak Hyundai/Kia-published output by version
EngineModel yearsFuelPeak hpPeak torque (lb-ft)Documented problemsRecalls
2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class)2011–2022Gasoline (direct injection)——38
2.4L MPI, including the first hybrids (2010–2016)2010–2016Gasoline (multi-point injection); hybrid in Sonata Hybrid and Optima Hybrid——13

CarWhere lists 4 documented problems and 11 NHTSA recalls for the Theta II (2.4L and 2.0T), each with a source.

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class)

The direct-injected 2.4L and 2.0T are the engines in the Engine I settlement: 2011–2019 Sonata, 2013–2019 Santa Fe Sport, 2014–2015 and 2018–2019 Tucson, 2011–2019 Optima, 2012–2019 Sorento and 2011–2019 Sportage, with certain 2019 models excluded once KSDS was built in at the factory.

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class) specifications

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class): design facts (2011–2022)
SpecificationValue
Engine familyTheta II (court class definition: “genuine Theta II 2.0 liter or 2.4 liter gasoline direct injection engine”)[2]
Displacements2.4 L naturally aspirated; 2.0 L turbocharged[2]
Fuel systemGasoline direct injection (EPA code SIDI)[1]
Bore × stroke, 2.4L88 × 97 mm (weak source)[3]
Bore × stroke, 2.0T86 × 86 mm (weak source)[3]
Engine codesG4KJ (2.4 GDI), G4KH (2.0 T-GDI) (weak source)[3]
EPA listing, Hyundai Sonata2.4 L 4-cyl SIDI 2011–2019; 2.0 L turbo SIDI 2011–2019[1]
EPA listing, Kia Optima2.4 L 4-cyl SIDI 2011–2020; 2.0 L turbo SIDI 2011–2020[1]
EPA listing, Kia Sportage2.4 L 4-cyl SIDI 2014–2022; 2.0 L turbo SIDI 2011–2022[1]
Settlement class size3,956,568 Hyundai and Kia class vehicles[2]
2019 models in the classOnly those built before KSDS was incorporated into production[2]
Settlement valuation$1,305,396,814, per the parties' expert as described in the final approval order[2]

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class) horsepower and torque by year

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class): Hyundai/Kia-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2011–2019Hyundai Sonata 2.4L GDINot stated in the EPA record; CarWhere could not verify a Hyundai/Kia US rating for this application——[1]
2011–2019Hyundai Sonata 2.0TNot stated in the EPA record; CarWhere could not verify a Hyundai/Kia US rating for this application——[1]
2011–2020Kia Optima 2.4L GDI and 2.0TNot stated in the EPA record; CarWhere could not verify a Hyundai/Kia US rating for this application——[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class)?

Models and model years offered with the 2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class)
ModelModel yearsNotes
Hyundai Sonata (2.4L GDI, 2.0T)2011–2019All 2011–2018 and certain 2019 models are settlement class vehicles
Hyundai Santa Fe Sport (2.4L GDI, 2.0T)2013–2019All 2013–2018 and certain 2019 models are class vehicles; EPA files it under Santa Fe
Hyundai Tucson (2.4L GDI)2014–2015, 2018–2021Class covers 2014–2015, 2018 and certain 2019 models; EPA lists the 2.4L SIDI through 2021
Kia Optima (2.4L GDI, 2.0T)2011–2020All 2011–2018 and certain 2019 models are class vehicles
Kia Sorento (2.4L GDI, 2.0T)2012–2020All 2012–2018 and certain 2019 models are class vehicles; EPA lists the 2.0T for 2016–2018
Kia Sportage (2.4L GDI, 2.0T)2011–2022All 2011–2018 and certain 2019 models are class vehicles

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class) problems and what to check

Connecting-rod bearing wear and engine seizure (2011–2019)

Major repair

Hyundai's 2015 recall said metallic debris from crankshaft machining may not have been fully removed, restricting oil flow to the connecting-rod bearings of 2011–2012 Sonatas built at Hyundai Motor Manufacturing Alabama between December 11, 2009 and April 12, 2012. The 2017 Hyundai and Kia recalls described machining errors that can cause premature bearing wear. A worn bearing can lead to engine stall, seizure or failure. Remedies were inspection and short-block or engine replacement, and Hyundai extended the short-block warranty on the 2011–2012 Alabama-built Sonatas to 10 years/120,000 miles for original and later owners.[4][5][6][2][7]

Symptoms

  • A metallic, cyclic knocking noise from the engine
  • Check-engine light and a reduced-power engine protection mode on KSDS-equipped cars
  • Engine stall or seizure while driving

Check before buying

  • Run the VIN at nhtsa.gov/recalls for 15V568 (2011–2012 Sonata), 17V226 (2013–2014 Sonata, Santa Fe Sport) or 17V224 (Kia)
  • Ask a dealer to confirm the KSDS software update is on the car; the settlement's lifetime warranty requires it
  • Keep maintenance records; the Kia settlement site advises keeping records for service after August 18, 2020

Program: Recalls 15V568, 17V226 and 17V224; KSDS Product Improvement Campaign; lifetime short-block warranty under In re: Hyundai and Kia Engine Litigation (C.D. Cal.)

High-pressure fuel pipe leaks after engine replacement (2011–2018)

Major repair

After the bearing recalls, both brands found the high-pressure fuel pipe at the fuel-pump outlet could be damaged, misaligned or under-torqued during engine replacement, allowing a fuel leak. Hyundai's 18V934 covers 2011–2014 Sonatas and 2013–2014 Santa Fe Sports repaired under 15V-568 or 17V-226. Kia's 18V907 covers 2011–2017 Optima, 2012–2017 Sorento and 2011–2018 Sportage models that received a replacement engine under 17V-224, under warranty or through the KSDS campaign.[8][9][2]

Symptoms

  • Fuel smell from the engine bay
  • Visible fuel at the high-pressure pump outlet

Check before buying

  • If the car ever had a replacement engine, check the VIN for 18V934 (Hyundai) or 18V907 (Kia)
  • Ask for the dealer record showing the fuel pipe was inspected or replaced

Program: Safety recalls 18V934 (Hyundai) and 18V907 (Kia); free inspection and fuel-pipe replacement

Low-pressure fuel hose cracking (2013–2014 Sonata and Optima) (2013–2014)

Moderate

The low-pressure fuel hose feeding the direct-injection pump can crack over time from engine-bay heat. Kia's 20V100 covers 2013–2014 Optimas with the 2.4L GDI or 2.0L GDI Turbo; dealers replace a damaged hose or add heat-protective tape. Hyundai first recalled 2013–2014 Sonatas under 20V121 and later replaced that remedy with 22V312, under which dealers replace the hose; cars that got only tape under 20V121 need the new remedy.[10][11][12]

Symptoms

  • Fuel odor
  • Fuel seepage near the low-pressure hose

Check before buying

  • Check the VIN for 22V312 (Sonata) or 20V100 (Optima)
  • On a Sonata repaired under 20V121, confirm the hose itself was replaced

Program: Safety recalls 20V121/22V312 (Hyundai) and 20V100 (Kia)

2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class) recalls

NHTSA safety recalls related to the 2.4L GDI and 2.0L turbo GDI (2011–2019 settlement class) (campaign numbers link to NHTSA)
NHTSA campaignReportedVehiclesSummary
15V5682015-09-102011–2012 Hyundai Sonata (2.0L and 2.4L GDI) built Dec. 11, 2009 – Apr. 12, 2012 in Alabama470,000 vehiclesCrankshaft machining debris can restrict oil to the rod bearings, causing knock and possible engine failure. Dealers inspect and replace the engine as needed; short-block warranty extended to 10 years/120,000 miles.
17V2262017-03-312013–2014 Hyundai Sonata and Santa Fe Sport572,000 vehiclesMachining errors can cause premature bearing wear. Dealers inspect the engine and replace the short block as needed, free of charge.
17V2242017-03-312011–2014 Kia Optima, 2012–2014 Sorento, 2011–2013 Sportage618,160 vehiclesMachining errors can cause premature bearing wear and engine seizure. Dealers inspect the engine and replace it if necessary, free of charge.
18V9342018-12-282011–2014 Hyundai Sonata, 2013–2014 Santa Fe Sport (previously repaired under 15V-568/17V-226)150,730 vehiclesThe high-pressure fuel pipe may have been damaged or mis-torqued during engine replacement and can leak. Dealers inspect and replace it as needed.
18V9072018-12-192011–2017 Kia Optima, 2012–2017 Sorento, 2011–2018 Sportage with a replacement engine71,653 vehiclesSame high-pressure fuel pipe risk for engines replaced under 17V-224, warranty or the KSDS campaign. Dealers inspect and replace the pipe as needed.
20V1002020-02-212013–2014 Kia Optima (2.4L GDI, 2.0L GDI Turbo)141,774 vehiclesThe low-pressure fuel hose can crack from engine-bay heat. Dealers replace a damaged hose or install heat-protective tape.
20V1212020-02-282013–2014 Hyundai Sonata216,799 vehiclesLow-pressure fuel hose can crack from heat. Original remedy: inspect, replace or tape. Replaced by 22V312.
22V3122022-05-062013–2014 Hyundai Sonata215,171 vehiclesReplacement remedy for 20V121: dealers replace the low-pressure fuel hose, including on cars that received only tape.

2.4L MPI, including the first hybrids (2010–2016)

Before and alongside the GDI engine, a port-injected 2.4L Theta II powered the 2010–2012 Santa Fe, 2010–2013 Tucson, Kia's 2011–2013 Sorento and Sportage and 2010–2013 Forte/Forte Koup, plus the 2011–2015 Sonata Hybrid and 2011–2016 Optima Hybrid. These engines are in the 2024 Engine II settlement.

2.4L MPI, including the first hybrids (2010–2016) specifications

2.4L MPI, including the first hybrids (2010–2016): design facts (2010–2016)
SpecificationValue
Engine familyTheta II 2.4-liter multi-port fuel injection (MPI), per the Engine II settlement[13]
Hybrid versionsTheta II 2.4-liter MPI in the 2011–2015 Sonata Hybrid and 2011–2016 Optima Hybrid[13]
EPA listing, Hyundai Santa Fe2.4 L 4-cyl (no direct-injection code) 2010–2012[1]
EPA listing, Hyundai Tucson2.4 L 4-cyl (no direct-injection code) 2010–2013[1]
EPA listing, Kia Sorento2.4 L 4-cyl (no direct-injection code) 2011–2013[1]
EPA listing, Sonata Hybrid2.4 L 4-cyl hybrid, 270V Li-ion battery, 2011–2015[1]
Engine codeG4KE (2.4 MPI) (weak source)[3]

2.4L MPI, including the first hybrids (2010–2016) horsepower and torque by year

2.4L MPI, including the first hybrids (2010–2016): Hyundai/Kia-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2011–2015Hyundai Sonata Hybrid (2.4L MPI)Not stated in the EPA record; CarWhere could not verify a Hyundai/Kia US rating for this application——[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the 2.4L MPI, including the first hybrids (2010–2016)?

Models and model years offered with the 2.4L MPI, including the first hybrids (2010–2016)
ModelModel yearsNotes
Hyundai Santa Fe2010–2012
Hyundai Tucson2010–2013
Hyundai Sonata Hybrid2011–2015
Kia Optima Hybrid2011–2016
Kia Sorento2011–2013
Kia Sportage2011–2013
Kia Forte and Forte Koup2010–2013Settlement lists these with the Theta II 2.4L MPI

2.4L MPI, including the first hybrids (2010–2016) problems and what to check

Connecting-rod bearing failure (Engine II class) (2010–2016)

Major repair

The Engine II case alleged the same rod-bearing defect in other Hyundai and Kia engines, including the 2.4L MPI. Recalls 20V746 (Hyundai) and 20V750 (Kia) in December 2020 and 23V877 (2011 Kia Sorento) in December 2023 cover models that include 2.4L MPI applications; dealers inspect the engine, replace it if bearing damage is found and install KSDS software. The settlement extends the powertrain warranty to 15 years or 150,000 miles from original retail delivery for damage caused by connecting-rod bearing failure.[13][14][15][16][17]

Symptoms

  • Engine knock
  • Check-engine light with engine protection mode after KSDS is installed
  • Stalling; Kia's 20V750 and 23V877 filings cite engine-compartment fire risk

Check before buying

  • Run the VIN for 20V746, 20V750 or 23V877
  • Confirm KSDS has been installed; the 15-year/150,000-mile warranty generally requires it
  • Hyundai vehicles under recalls 20V746 and 21V727 are exempt from the KSDS requirement, per the Hyundai settlement site

Program: In re: Hyundai and Kia Engine Litigation II: 15-year/150,000-mile extended warranty for rod-bearing damage; recalls 20V746, 20V750, 23V877

2.4L MPI, including the first hybrids (2010–2016) recalls

NHTSA safety recalls related to the 2.4L MPI, including the first hybrids (2010–2016) (campaign numbers link to NHTSA)
NHTSA campaignReportedVehiclesSummary
20V7462020-12-012015–2016 Veloster, 2012 Santa Fe, 2011–2013 and 2016 Sonata Hybrid128,948 vehiclesConnecting-rod bearings may wear prematurely. Dealers inspect, replace the engine if bearing damage is found and install a new KSDS software update. The filing lists models, not engines; the 2012 Santa Fe and 2011–2013 Sonata Hybrid entries are 2.4L MPI applications in the Engine II settlement.
20V7502020-12-022012–2013 Sorento, 2012–2015 Forte/Forte Koup, 2011–2013 Optima Hybrid, 2014–2015 Soul, 2012 Sportage294,756 vehiclesEngine-compartment fire can occur while driving. Dealers check for fuel and oil leaks, run an engine test, repair or replace the engine and update KSDS software.
23V8772023-12-212011 Kia Sorento79,812 vehiclesEngine-compartment fire can occur while driving. Dealers install KSDS software and replace the engine as necessary.

Theta II (2.4L and 2.0T) issues by model

The same engine shows up on these known-issues pages, with model-specific details.

Related Hyundai and Kia research

Confirm a car really has the Theta II (2.4L and 2.0T).

The engine a Hyundai or Kia left the factory with is part of its build record. The CarWhere Hyundai build sheet reconstructs factory colors, options and packages from licensed VIN-level build data — availability is checked free, and it is $9.99 only when detailed build data is found for that VIN.

Hyundai build sheet by VIN

Frequently asked questions

Which Hyundai and Kia models have the Theta II engine?

The court's class definition lists 2011–2019 Sonata, 2013–2019 Santa Fe Sport, 2014–2015 and 2018–2019 Tucson, 2011–2019 Optima, 2012–2019 Sorento and 2011–2019 Sportage with the Theta II 2.0L turbo or 2.4L GDI engine (2019 models only if built before KSDS was added). The 2.4L MPI version was used in earlier Santa Fe, Tucson, Sorento, Sportage and Forte models and the first Sonata and Optima hybrids.

What is the Kia/Hyundai engine settlement?

In re: Hyundai and Kia Engine Litigation, No. 8:17-cv-00838-JLS-JDE (C.D. Cal.), received final approval on May 10, 2021, and judgment was entered June 10, 2021. It extends the powertrain warranty on the engine short block to a lifetime warranty for class vehicles owned by individuals who completed the KSDS update, and it reimburses certain repair, towing, rental and fire-loss costs. The official Kia site is kiaenginesettlement.com.

Can I still file a claim under the Theta II settlement?

The deadline for most claim types, including past repairs and sold or traded-in vehicles, passed on August 9, 2021. According to Kia's settlement site, claims for towing, rental and other costs tied to a qualifying repair can still be filed within 90 days of the expense, and engine-fire loss and rebate claims within 90 days of an event after August 28, 2020. The lifetime warranty needs no claim form.

What is the KSDS update?

KSDS (Knock Sensor Detection System) is engine-monitoring software that watches for symptoms that can precede bearing failure. If it detects bearing wear, the check-engine light comes on and the car enters a temporary engine protection mode so it can be driven at reduced speed to a repair facility. Dealers install it free, and the lifetime warranty depends on it.

Does a 2019 Sonata or Optima have the lifetime engine warranty?

Only if it was built before KSDS was incorporated into production; those 2019 vehicles are in the class. Later 2019 models were built with KSDS and are not class vehicles. Kia owners can confirm by VIN through the settlement line, 1-888-952-4827.

What does the lifetime warranty cover?

Per Kia's settlement site, it covers the short block (engine block, crankshaft and bearings, connecting rods and bearings, and pistons) for bearing wear or damage regardless of mileage or ownership, including parts, labor and diagnosis. It can be denied for Exceptional Neglect, including failure to have KSDS installed, and it does not apply to used-car dealers or auction houses.

Sources

Ratings are Hyundai/Kia-published figures as cited; descriptions are CarWhere’s own summaries of the sources below. Repair costs appear only where a source states them and vary by shop and region.

  1. EPA fuel economy data: vehicles.csv (Hyundai and Kia listings by model year, displacement, cylinders, turbo and fuel-injection codes) — U.S. EPA / DOE (fueleconomy.gov)
  2. Order Granting Final Approval of Class Action Settlement and Attorneys' Fees, In re: Hyundai and Kia Engine Litigation, No. 8:17-cv-00838-JLS-JDE, Doc. 202 (C.D. Cal. May 10, 2021) — U.S. District Court, Central District of California (hosted on kiaenginesettlement.com)
  3. Hyundai Theta engine — Wikipedia (secondary reference)
  4. NHTSA recall 15V568: Connecting rod wear may result in engine stall (2011–2012 Sonata) — NHTSA (Hyundai Motor America filing)
  5. NHTSA recall 17V226: Bearing wear may result in engine seizure (2013–2014 Sonata, Santa Fe Sport) — NHTSA (Hyundai Motor America filing)
  6. NHTSA recall 17V224: Bearing wear may result in engine seizure (2011–2014 Optima, 2012–2014 Sorento, 2011–2013 Sportage) — NHTSA (Kia America filing)
  7. Kia Engine Settlement — Frequently Asked Questions — Kia America, Inc. (court-approved settlement website)
  8. NHTSA recall 18V934: High-pressure fuel pipe may leak (Hyundai engines replaced under 15V-568/17V-226) — NHTSA (Hyundai Motor America filing)
  9. NHTSA recall 18V907: High-pressure fuel pipe may leak (Kia engines replaced under 17V-224, warranty or KSDS campaign) — NHTSA (Kia America filing)
  10. NHTSA recall 20V121: Low-pressure fuel hose may crack and leak (2013–2014 Sonata) — NHTSA (Hyundai Motor America filing)
  11. NHTSA recall 22V312: Low-pressure fuel hose may crack and leak (2013–2014 Sonata, replacement remedy) — NHTSA (Hyundai Motor America filing)
  12. NHTSA recall 20V100: Low-pressure fuel hose may crack and leak (2013–2014 Optima 2.4L GDI / 2.0L GDI Turbo) — NHTSA (Kia America filing)
  13. Settlement Agreement, In re: Hyundai and Kia Engine Litigation II, No. 8:18-cv-02223-JLS-JDE, Doc. 79-2 (filed Sept. 26, 2022) — U.S. District Court, Central District of California (hosted on hma-e2settlement.com)
  14. Hyundai Engine II Class Action Settlement — official settlement website (In re: Hyundai and Kia Engine Litigation II, No. 8:18-cv-02223-JLS-JDE, C.D. Cal.) — Settlement administrator (Angeion Group) for Hyundai Motor America
  15. NHTSA recall 20V746: Engine damage may cause stall or fire (2015–2016 Veloster, 2012 Santa Fe, 2011–2013 and 2016 Sonata Hybrid) — NHTSA (Hyundai Motor America filing)
  16. NHTSA recall 20V750: Engine damage may cause fire (2012–2013 Sorento, 2012–2015 Forte/Forte Koup, 2011–2013 Optima Hybrid, 2014–2015 Soul, 2012 Sportage) — NHTSA (Kia America filing)
  17. NHTSA recall 23V877: Engine compartment fire (2011 Sorento) — NHTSA (Kia America filing)

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Independent reference compiled by CarWhere — not affiliated with or endorsed by Hyundai Motor America, Hyundai Motor Company or Hyundai Motor Group. Hyundai and the model names are trademarks of their owners.