Hyundai Sonata 2.4 Engine for Sale | OEM Used Theta II 2.4 Liter Inline-4 Engine

Hyundai 2.4L naturally-aspirated inline-4 from the Theta engine family. The Hyundai Sonata 2.4 Theta II engine is the OEM Hyundai Theta II 2.4L inline-4 from the Theta engine family, used extensively across the Hyundai / Kia lineup including Sonata, Optima, Tucson, Sportage, and Forte applications. In the Sonata application, the Theta II 2.4L produces 175-200 HP depending on variant (MPI or GDI). Specifications: 2.4 liters displacement (2,359 cc), inline-4 cylinder, aluminum block and head, DOHC with 4 valves per cylinder (16 valves total), D-CVVT dual continuously variable valve timing, MPI or GDI fuel injection depending on variant, engine codes G4KE (MPI) and G4KH (GDI), timing chain driven, naturally aspirated. The Theta II has well-documented engine knock and bearing failure issues that prompted multiple recalls and class action settlements from Hyundai / Kia.

Multiple recalls and class action settlements due to bearing failures. The Theta II engine family has a well-documented reliability history that buyers MUST understand before purchase. Primary failure mode: connecting rod bearing failure, often resulting in engine knock followed by complete engine failure. The bearings can fail due to manufacturing defects in the engine block oil supply passages on certain production runs. NHTSA recalls: multiple recalls were issued by Hyundai and Kia covering Theta II engines across Sonata, Optima, Sorento, Sportage, and other applications. Recall numbers include 15V-568, 17V-226, 17V-345, 18V-249, and several subsequent expansions. Class action settlements: multiple class action lawsuits resulted in extended warranty programs (up to 12 years / 120,000 miles for affected engines), engine replacements, and reimbursement for affected owners. KSDS (Knock Sensor Detection System): Hyundai installed knock detection software on many recalled vehicles. Engine fires: in some cases Theta II failures resulted in engine fires, prompting additional safety recalls. Recall eligibility check: before purchasing, check your VIN against Hyundai's recall database.

Multiple Hyundai / Kia applications. The Theta II 2.4L is used across the Hyundai / Kia lineup: Hyundai Sonata 2.4 (this listing application, 2011-2019), Hyundai Tucson 2.4 (2010-2015, some variants), Hyundai Santa Fe Sport 2.4 (2013-2018), Kia Optima 2.4 (2011-2019), Kia Sportage 2.4 (2011-2016), Kia Forte 2.4 (some variants), Kia Sorento 2.4 (2014-2018, some variants). Cross-application between these chassis is possible but requires careful ECU, accessory, and engine mount verification. All of these applications share the well-documented Theta II reliability history with recall coverage; specific recall eligibility varies by VIN and year.

Two generation chassis with Theta II 2.4L variants. YF Sonata (2011-2014): sixth-generation Sonata with Theta II 2.4 MPI standard and Theta II 2.4 GDI on some trims. LF Sonata (2015-2019): seventh-generation Sonata facelift, with Theta II 2.4 GDI predominant. Engine pairing: 6-speed automatic transmission standard, available as front-wheel drive only. Trim levels: GLS, SE, Limited, Sport (varies by year). The MPI variant uses port fuel injection while the GDI variant uses direct fuel injection; the variants are NOT directly interchangeable without ECU, fuel system, and accessory verification.

Two Hyundai engines in. The Hyundai Theta II 2.4L (this listing) is the smaller inline-4 from Hyundai's Theta engine family. For broader Hyundai engine family context across our catalog, the Hyundai Genesis Coupe 3.8 Lambda II engine is the Hyundai Lambda II 3.8L V6 naturally-aspirated for the 2010-2016 Hyundai Genesis Coupe (producing 306 HP MPI early or 348 HP GDI later), the larger V6 from a different Hyundai engine family (Lambda II) used across Genesis Coupe / Genesis Sedan / Equus / Azera / Sonata 3.8 / Veracruz applications. Two Hyundai engine listings across : Lambda II 3.8L V6 for Hyundai larger applications, (this listing) Theta II 2.4L inline-4 for Hyundai / Kia mid-size applications. Both engine families have been used widely across the Hyundai / Kia lineup but represent different architectures and reliability profiles.

Check VIN against Hyundai recall database. Before purchasing or after acquiring a Theta II engine, check your VIN against Hyundai's recall database to determine if your specific application is covered by recall or extended warranty. Multiple NHTSA recalls cover Theta II engines (15V-568, 17V-226, 17V-345, 18V-249 and subsequent expansions). Hyundai also offers an extended warranty program covering Theta II engines for up to 12 years / 120,000 miles for affected VINs. To check: visit nhtsa.gov or hyundaiusa.com and enter your VIN. If your VIN is covered, you may be eligible for free engine replacement (covered by Hyundai), extended warranty coverage, or reimbursement for prior repairs. This honest disclosure helps you understand what coverage may apply to your specific engine before or after purchase.

Connecting rod bearing inspection, KSDS verification, oil maintenance. After acquiring a used Hyundai Theta II 2.4L engine, budget for these items. Connecting rod bearing inspection: have a qualified technician inspect the connecting rod bearings during the warranty period (engine knock or oil pressure issues are early warning signs of bearing failure). KSDS (Knock Sensor Detection System) verification: ensure the KSDS software is installed and functional if your VIN is covered by recall. Strict 5,000 mile oil change intervals: use Hyundai-recommended 5W-20 or 5W-30 oil (depending on year); extended oil change intervals exacerbate bearing wear. Carbon cleaning (GDI variant only): walnut shell blasting every 60,000-100,000 miles for direct injection carbon buildup. Recall service if applicable: if your VIN is covered by recall, complete the recall service through a Hyundai dealer (free of charge). The Theta II can deliver reliable service when properly maintained and when the manufacturing defect is not present in the specific engine.

No. There is no core return required.