The Theta II 2.0L and 2.4L gasoline direct-injection engines have been recalled and re-recalled across more than 4 million Hyundai and Kia vehicles for connecting-rod bearing wear that can seize the engine or start a fire. A nationwide class action settlement (Flaherty v. Hyundai, In re Hyundai and Kia Engine Litigation, C.D. Cal.) added a lifetime engine warranty and a knock sensor detection software remedy (KSDS).
Under the settlement, every eligible Theta II engine is covered by a lifetime warranty against short block failure for the original and subsequent owners. KSDS software install is required to keep the warranty active.
Theta II engines built at Hyundai's Alabama plant and Kia's Georgia plant from roughly 2010 onward shipped with manufacturing debris in the crankshaft oil passages. Restricted oil flow to the connecting-rod bearings caused premature wear, knocking, oil pressure loss, and ultimately seizure or a thrown rod that punches a hole in the block. In some cases hot oil contacted the exhaust and started under-hood fires. The defect was first acknowledged in NHTSA recall 15V-568 (Sonata) and expanded over the next decade through more than a dozen related campaigns. Hyundai and Kia agreed to a knock sensor detection system (KSDS) software update that listens for the early high-frequency rattle of bearing wear and triggers a limp mode plus check engine light. Vehicles that pass KSDS get the lifetime warranty.
| Model | Years | Engine | Lead NHTSA # | Severity |
|---|---|---|---|---|
| Hyundai Sonata | 2011-2014 | 2.0L / 2.4L Theta II GDI | 15V-568, 17V-226 | Critical |
| Hyundai Santa Fe Sport | 2013-2014 | 2.4L Theta II GDI | 17V-226 | Critical |
| Hyundai Tucson | 2014-2015 | 2.4L Theta II | 20V-159 | High |
| Hyundai Elantra (limited) | 2017-2020 | 2.0L Nu (related claim) | 20V-159 family | Medium |
| Kia Optima | 2011-2014 | 2.0L / 2.4L Theta II GDI | 17V-224 | Critical |
| Kia Sorento | 2012-2014 | 2.4L Theta II GDI | 17V-224 | Critical |
| Kia Sportage | 2011-2014 | 2.4L Theta II GDI | 17V-224 | Critical |
| Kia Soul | 2012-2016 | 2.0L Nu (companion claim) | 20V-741 | High |
Data sourced from NHTSA recall database (nhtsa.gov/recalls), manufacturer technical service bulletins, and publicly filed class-action documents. Always verify with your VIN before purchase or repair.
Recalls are tied to specific VINs, not just model years. Run yours through these free tools before you buy, sell, or schedule a repair:
Use our free VIN decoder to pull build info, or run a free AI diagnosis if you already have symptoms.
In re Hyundai and Kia Engine Litigation, Case No. 8:17-cv-00838 (C.D. Cal.) consolidated 12+ class actions. Final approval in 2021 valued the settlement at over $760 million plus the cost of the lifetime engine warranty, KSDS software, reimbursement of past repairs, rental cars during repair, and goodwill payments. The companion Flaherty v. Hyundai action and the related Mendoza v. Kia case set the framework for the warranty extension.
Run KSDS at any Hyundai or Kia dealer (free), keep every oil-change receipt, and if the engine knocks, ticks, or stalls have the dealer document it the same day. Past out-of-pocket engine repairs are reimbursable. Total loss (fire) claims go through Hyundai/Kia consumer affairs. State lemon-law clocks restart with each unresolved repair attempt.
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Yes. The settlement engine warranty stays with the VIN, not the original owner, as long as KSDS has been installed and recommended maintenance is documented.
Knock Sensor Detection System is a free software update that listens for the early high-frequency knock of rod-bearing wear. Installing it is required to keep the lifetime engine warranty.
Yes. The settlement requires a comparable loaner or rental reimbursement while a covered short block or long block replacement is in progress.
File a reimbursement claim through the settlement administrator. Receipts, repair orders, and proof of payment are required.
No. The settlement covers Theta II 2.0L and 2.4L naturally aspirated GDI engines plus the 2.0L Nu in some models. Turbocharged 2.0T Theta II engines have a separate recall (17V-225).
You can opt out of the class for damages above warranty value, but the settlement releases most consumer claims. Talk to a product-liability attorney before signing any release.