Hyundai Class Action Lawsuit Engine, $1.3B Settlement for Theta II Defects—Lifetime Warranty, Reimbursement & How to Claim
Hyundai Motor America and Kia America agreed to a $1.3 billion settlement to resolve class action litigation alleging Theta II, Nu GDI, and Gamma GDI engines are defective, causing engine seizure, stalling, failures, and fires. Final approval was granted June 10, 2021, covering approximately 2.21 million vehicles including certain 2010-2021 Hyundai models. Eligible vehicle owners receive lifetime engine warranty, free inspections and repairs, reimbursements for past expenses, and software safety updates.
What Hyundai Allegedly Did Wrong With Engine Defects
The lawsuits alleged Hyundai and Kia Class Vehicles suffer from a defect that can cause engine seizure, stalling, engine failure, and engine fire, that engine seizure or stalling can be dangerous if experienced, and that some owners and lessees have been improperly denied repairs under the vehicle’s warranty. Engine defect—a manufacturing or design flaw that causes vehicle components to malfunction or fail prematurely—forms the core of product liability claims when automakers allegedly knew about problems but failed to disclose them or issue adequate remedies.
The specific allegations centered on connecting rod bearing failures in gasoline direct injection engines. According to the complaint, these connecting rod bearings can fracture and release metal debris into the engine oil, and the oil filter is unable to filter everything out, meaning the contaminated oil is circulated through the engine, causing damage to components until the engine fails unexpectedly. As the connecting rod bearings continue to fracture, the acceptable tolerances between the bearings, the connecting rod, and the crankshaft rapidly deteriorate, eventually leading to a “knocking” sound. In some cases, the piston can allegedly break through the engine block and other engine components can be damaged.
Which Hyundai Vehicles and Engine Types Are Covered
The first major settlement covers approximately 1.05 million Hyundai vehicles: 2011-2019 Sonata (Theta II 2.0L or 2.4L GDI engines and certain 2019 models manufactured before Knock Sensor Detection System technology was incorporated), 2013-2019 Santa Fe Sport (Theta II 2.0L or 2.4L GDI), 2014-2015 and 2018-2019 Tucson (Theta II 2.0L or 2.4L GDI, excluding 2016-2017 model years), and certain 2019 Tucson vehicles equipped with or replaced with a genuine Theta II 2.0 liter or 2.4 liter gasoline direct injection engine within OEM specifications.
A second settlement covering approximately 1.05 million additional Hyundai vehicles was preliminarily approved February 8, 2023, and received final approval September 8, 2023. This expanded settlement includes: 2010-2012 Santa Fe (Theta II 2.4L MPI engine), 2011-2019 Sonata Hybrid/Plug-In Hybrid (Theta II 2.4L MPI Hybrid and Nu 2.0 GDI Hybrid engines), 2010-2021 Tucson (Theta II 2.4L MPI and Nu 2.0 GDI engines), 2014 Elantra Coupe (Nu 2.0 GDI), 2014-2016 Elantra (Nu 2.0 GDI), 2014-2020 Elantra GT (Nu 2.0 GDI), and 2012-2017 Veloster (Gamma 1.6L GDI).
Settlement Benefits and Compensation Available
The settlements provide nine categories of relief worth $1.3 billion combined. The most significant benefit is a 15-year or 150,000-mile extended warranty covering all costs associated with inspections and repairs of damage caused by connecting rod bearing failure. This warranty applies automatically to all covered vehicles that receive the free Knock Sensor Detection System software update.
Owners who have not already done so are eligible to schedule a free inspection under the warranty within 90 days of the settlement’s final approval to determine whether their vehicle has any symptoms of connecting rod bearing failure. The settlement also provides reimbursement for repairs and out-of-pocket expenses, goodwill payments of $140 for certain claimants, a rebate program, and compensation for vehicles that were destroyed or declared total losses due to engine failures or fires.
Specific compensation categories include reimbursement for engine repair costs paid out-of-pocket, reimbursement for towing expenses related to engine failures, reimbursement for rental car costs during engine repairs, compensation for diminished vehicle value if engine problems affected resale value, and payments for total vehicle loss when engines caught fire or failed catastrophically beyond repair.
Eligibility Requirements and Required Documentation
To receive benefits from the Hyundai Theta engine settlements, Class Members must have owned or leased covered vehicles during the relevant time periods. You did not have to experience stalling, engine seizure, engine failure, or a vehicle fire to be included—simply owning or leasing a covered vehicle makes you eligible for the lifetime warranty benefit once the Knock Sensor Detection System software update is installed.
However, to receive reimbursement for past expenses or other monetary compensation, you must submit a valid claim form with supporting documentation. Required documents vary by claim type but typically include vehicle identification number, proof of ownership or lease agreement, repair invoices from Hyundai dealerships or independent mechanics showing engine-related work, receipts for towing services related to engine failures, rental car receipts with dates corresponding to engine repair periods, and documentation of engine fire incidents or total vehicle loss.
The case is consolidated as In re: Hyundai and Kia Engine Litigation II, Case No. 8:18-cv-02223, in the U.S. District Court for the Central District of California.
Current Status and Important Deadlines
The original Theta II GDI engine settlement received final approval and judgment was entered on June 10, 2021. The claim deadline for that settlement was April 12, 2021. Payments for approved claims were mailed 30 days after the effective date when all appeals were exhausted.
The second settlement covering Theta II MPI, Nu GDI, and Gamma GDI engines received preliminary approval on February 8, 2023, with the final approval hearing held September 8, 2023. While the claim deadlines for both settlements have passed, the lifetime warranty remains available to all covered vehicle owners who install the Knock Sensor Detection System software update, regardless of whether they filed claims during the original claims periods.
What You Must Know About the Settlements
Whether You Can Still Benefit If You Missed the Claim Deadline
Even if you missed the original claim deadlines, you can still receive the lifetime engine warranty—the most valuable component of the settlements for most vehicle owners. This warranty covers all costs associated with inspections and repairs of damage caused by connecting rod bearing failure, as long as you have the Knock Sensor Detection System software update installed.
Schedule the free software installation at any Hyundai dealership by calling and referencing the “953 campaign” update or the Knock Sensor Detection System. Once installed, your covered vehicle receives lifetime warranty protection on the engine’s short block assembly, consisting of the engine block, crankshaft and bearings, connecting rods and bearings, and pistons, except in cases of exceptional neglect.
How the Knock Sensor Detection System Protects Your Engine
Each covered vehicle is part of an ongoing product improvement campaign to install an engine monitoring technology called a knock sensor detection system. The technology uses software innovations and leverages existing engine sensors to continuously monitor for symptoms that may precede an engine failure. The system can detect abnormal engine conditions and alert drivers before catastrophic failure occurs, potentially preventing dangerous situations where engines seize while driving.
The software update is installed free of charge for all vehicles in the settlement by Hyundai and Kia dealers. Installation takes approximately one hour and requires no parts replacement—it’s purely a software reprogramming of the engine control module.
What to Do Next to Protect Your Rights
How to Verify If Your Vehicle Is Covered
Visit the official settlement website at https://www.hyundaithetaenginesettlement.com/ and enter your Vehicle Identification Number to determine if your vehicle is included in either settlement. The VIN is located on a small placard on the top left of your dashboard, visible through the windshield, or on your vehicle registration documents.
If the website confirms your vehicle is covered, schedule the free Knock Sensor Detection System software update immediately, even if you haven’t experienced engine problems. This update activates your lifetime warranty and provides ongoing engine monitoring protection.
Where to Find Official Settlement Information and Resources
The court-approved settlement website provides comprehensive information including the full settlement agreements, frequently asked questions, claim forms for those eligible for reimbursement claims, and contact information for the settlement administrator.
Contact the settlement administrator at 1-866-944-7620 for questions about eligibility, warranty coverage, or how to schedule the software update. Representatives can verify your vehicle’s inclusion in the settlement and provide guidance on next steps.
For related automotive defect litigation, see the Toyota UA80 transmission lawsuit over alleged automatic gearbox defects and the Subaru class action lawsuit 2025 EyeSight settlement, which demonstrate similar patterns of manufacturers issuing technical service bulletins for known defects but delaying recalls or warranty coverage.
How to Document Ongoing Engine Problems
If you’re experiencing engine symptoms like knocking sounds, unusual vibrations, warning lights, stalling, or difficulty starting, document everything immediately. Take videos of abnormal engine noises with your phone, including date and time stamps. Photograph dashboard warning lights as they appear. Keep detailed logs noting when symptoms occur, driving conditions, mileage, and what the engine was doing.
Take your vehicle to a Hyundai dealership and specifically request inspection under the settlement warranty for connecting rod bearing failure symptoms. Ensure the service advisor documents all your reported symptoms in the repair order, even if they cannot immediately replicate the problem. Request copies of all diagnostic reports, inspection results, and repair orders, whether or not warranty coverage is approved.
Frequently Asked Questions About the Hyundai Engine Lawsuit
Which Hyundai Vehicles Are Included in the Engine Class Action Lawsuit?
Covered vehicles include 2010-2021 Hyundai models with Theta II GDI, Theta II MPI, Nu GDI, or Gamma GDI engines, including Sonata, Santa Fe, Tucson, Elantra, and Veloster. Enter your VIN at HyundaiThetaEngineSettlement.com to verify coverage.
What Engine Defect Is the Hyundai Lawsuit About?
The lawsuits allege connecting rod bearings in certain Hyundai engines fracture and release metal debris into engine oil, causing progressive damage that leads to engine seizure, stalling, failure, and in some cases fires without warning.
How Much Money Will I Get From the Hyundai Engine Settlement?
Monetary compensation varied by claim type and is no longer available since claim deadlines passed. However, all covered vehicle owners still qualify for the lifetime engine warranty worth thousands of dollars in potential repair coverage.
Can I Still Get the Lifetime Warranty If I Missed the Claim Deadline?
Yes. The lifetime warranty remains available to all owners of covered vehicles who install the free Knock Sensor Detection System software update, regardless of whether they filed monetary claims during the original claims periods.
What If I Sold My Hyundai Vehicle Already?
The lifetime warranty transfers with the vehicle to subsequent owners as long as the Knock Sensor Detection System software update was installed. New owners can verify warranty coverage using the vehicle’s VIN at the settlement website.
How Do I Schedule the Free Software Update?
Contact any Hyundai dealership and reference the “953 campaign” update or the Knock Sensor Detection System installation. The update is free and takes approximately one hour.
What If Hyundai Denied My Warranty Claim Before?
If Hyundai previously denied engine warranty coverage for connecting rod bearing-related failures, and your vehicle is covered by the settlement, you may now be entitled to free repairs under the lifetime warranty or reimbursement if you paid out-of-pocket and filed a claim before the deadline.
Last Updated: January 16, 2026
Disclaimer: This article provides general information about the Hyundai engine class action settlements and is not legal advice. For specific questions about your vehicle or warranty coverage, contact the settlement administrator or consult with a qualified attorney.
Take Action: If you own a 2010-2021 Hyundai with Theta II, Nu GDI, or Gamma GDI engines, verify your vehicle’s coverage at HyundaiThetaEngineSettlement.com and schedule your free software update immediately to activate lifetime engine warranty protection.
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About the Author
Sarah Klein, JD, is a licensed attorney and legal content strategist with over 12 years of experience across civil, criminal, family, and regulatory law. At All About Lawyer, she covers a wide range of legal topics — from high-profile lawsuits and courtroom stories to state traffic laws and everyday legal questions — all with a focus on accuracy, clarity, and public understanding.
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