On March 31, 2017, Kia Motors America (Kia) filed a Defect Information Report (DIR) recalling 618,160 MY 2011-2014 Optima, MY 2012-2014 Sorento, and MY 2011-2013 Sportage vehicles with "Theta II" engines (Recall No. 17V-224)."Theta II" engines are a family of engines used by both Kia and Hyundai Motor America (Hyundai). Kia's DIR described the defect as an issue involving manufacturing debris as well as a machining process causing an uneven surface roughness which could restrict oil flow within the engine. Previously, on September 10, 2015, Hyundai filed a DIR recalling certain vehicles containing engines from the shared "Theta II" engine family, describing the defect as an issue involving manufacturing debris. Kia's March 31, 2017, DIR stated that Kia did not conduct a recall upon learning of Hyundai's September 2015 recall because Kia's "Theta II" engines were manufactured on a different production line and did not have the same manufacturing issue.This RQ is being opened to investigate both the timeliness and scope of Kia's "Theta II" engine recall, and Kia's compliance with reporting requirements.