P1326 on Hyundai

The 2.4L Theta II GDI engine offered in the pre-facelift Grandeur IG (2017-2019, before the 2.5 Smartstream replaced it) is part of the Theta II family covered by Hyundai's Korea-market recall and lifetime engine warranty. Machining debris and oil-supply problems cause connecting-rod bearing wear that progresses to rod knock, cylinder-wall scuffing, heavy oil consumption and, in the worst cases, sudden engine seizure while driving. MOLIT-supervised recalls installed the KSDS knock-sensor detection software, which puts the car in reduced-power limp mode (often with code P1326) when bearing noise is detected, and Hyundai extended a lifetime warranty on the engine for Grandeur HG/IG among roughly 520,000 Korean vehicles (4.69 million worldwide). Korean owner communities (Bobaedream, Clien) consistently report oil-consumption and knock cases on IG 2.4 cars.

On 2019-2021 Konas with the 2.0L Nu MPI engine, piston oil rings that were not consistently heat-treated can scuff the cylinder bores. This causes rising oil consumption, a progressively louder engine knock, and ultimately engine seizure or stall; a seized engine can throw a connecting rod and leak oil onto hot exhaust components, creating a fire risk.

The 2.0T and 2.4L Theta II engines in the Santa Fe are subject to a massive recall for connecting rod bearing failure and engine seizure. Manufacturing debris left in the engine during production restricts oil flow to the bearings, causing them to wear and fail. This can result in sudden engine seizure while driving — a serious safety issue. Hyundai has recalled millions of vehicles and extended warranties, but some owners report difficulty getting repairs authorized.

Manufacturing debris left in the crankshaft oil passages, combined with marginal oil supply to the connecting rod bearings, causes premature rod bearing wear on the Theta II 2.0T and 2.4L GDI engines shared with the Sonata/Optima. As the bearings wear, owners hear a metallic knocking/ticking that grows louder under load, often followed by sudden loss of power, stalling, and complete engine seizure; in some cases an underhood fire follows the seizure. The defect drove the Hyundai/Kia Theta II recalls, the Knock Sensor Detection System (KSDS) software campaign, and a ~$1.3B class-action settlement plus a $210M NHTSA civil penalty.

The Theta II GDI engine (2.4L MPI/GDI and 2.0T) suffers premature connecting-rod bearing wear. NHTSA determined that metal debris left from crankshaft machining, plus uneven crankpin surface roughness, restricts oil flow to the rod bearings, raising bearing temperatures and causing premature wear. A worn bearing produces a metallic, cyclic knocking noise that increases with RPM; if driven further the bearing fails, the engine can seize and stall while in motion, and a fractured rod can puncture the block, letting oil reach hot surfaces and start an engine-compartment fire. This is the defect behind multiple recalls (Campaign 132 / NHTSA 15V-218 for 2011-2012 2.0T/2.4 GDI built at HMMA; Campaign 198 / NHTSA 20V-746 covering Sonata Hybrid and others), a $210M NHTSA civil penalty consent order, and a ~$1.3B class-action settlement covering roughly 3.9M Hyundai/Kia owners.