Quick answer: Millions of Hyundai and Kia vehicles with the 2.0L and 2.4L Theta II GDI engines (roughly 2011–2019) can suffer connecting rod bearing wear that leads to engine knocking, failure and, in some cases, fire. A 2019 class action settlement gave eligible cars a lifetime warranty on related engine damage, conditional on a free knock-sensor software update. An engine replacement out of pocket typically costs $5,000–$9,000.
Affected models
Covered by the 2019 Theta II settlement (2.0L or 2.4L GDI engines). Check your VIN for exact coverage.
| Brand | Model | Years |
|---|---|---|
| Hyundai | Sonata | 2011 – 2019 |
| Hyundai | Santa Fe Sport | 2013 – 2018 |
| Hyundai | Santa Fe | 2019 |
| Hyundai | Tucson | 2014, 2015, 2018, 2019 |
| Kia | Optima | 2011 – 2019 |
| Kia | Sorento | 2011 – 2019 |
| Kia | Sportage | 2011 – 2019 |
Some vehicles were also part of separate safety recalls for engine failure and fire risk. Look up your VIN on the NHTSA recall site.
Symptoms of Theta II engine failure
- Knocking or ticking from the engine that gets louder with RPM.
- Check engine light flashing and the car going into a reduced-power mode (from the knock-sensor software).
- Oil consumption or low oil pressure warnings.
- Loss of power or the engine stalling while driving.
- Smoke or burning smell from the engine bay.
If you hear knocking, stop driving and have the car towed to a dealer.
The knock sensor software and lifetime warranty
- The Knock Sensor Detection System (KSDS) software monitors engine vibrations for signs of bearing wear. If it detects a problem, it flashes the check engine light and limits engine speed so you can get to a dealer safely.
- Under the settlement, eligible vehicles that received this free update got lifetime coverage for engine damage caused by connecting rod bearing wear, for original and later owners.
- If the update was never installed, ask a dealer to install it; it’s free.
Costs if you’re not covered
Typical prices, October 2026.
| Repair | Typical cost |
|---|---|
| Used engine installed | $3,500 – $6,000 |
| Remanufactured engine installed | $5,000 – $9,000 |
| New engine at a dealer | $7,000 – $10,000+ |
Repair or sell?
If the car is covered, let the dealer replace the engine. If coverage was denied (for example, because of missing maintenance records), ask for the decision in writing and contact the manufacturer’s customer care. If you end up paying yourself, compare the cost with the car’s value using the Repair or Replace Calculator or see How to Sell a Car With a Blown Engine.
Tips if you own one
- Keep oil change receipts; they help with warranty claims.
- Check the oil level monthly.
- Make sure the KSDS update and any recall work are done.
Sources
- NHTSA: Recalls lookup
- Repairer Driven News: Hyundai and Kia settle engine failure, fire class action lawsuit