May 24, 2017—The National Highway Traffic Safety Administration (NHTSA) is investigating a pair of recalls from Hyundai and Kia, which affected approximately 1.7 million vehicles and was related to engine defects, according to CNET.
The investigation is looking into the timeliness of the recalls, and it will determine whether or not the recall covered as many vehicles as it should have.
According to the original recall, which covered just 470,000 examples of the 2011-2012 Sonata sedan, debris leftover from the manufacturing process could affect the vehicles' engines, to the point where they may seize and cause the vehicle to stall.
After that recall, a whistleblower flew to Washington from South Korea to tell federal regulators that Hyundai did not recall as many vehicles as it should have, citing internal documents.
It took until March 31, 2017 for Hyundai to expand its recall to include another 572,000 vehicles, including the 2013-2014 Sonata and Santa Fe Sport. Kia finally issued a recall at that time, as well, covering about 618,000 examples of the 2011-2014 Optima, 2012-2014 Sorento and 2011-2013 Sportage.
"Kia Motors America has, and will continue to, cooperate and collaboratively work with the National Highway Traffic Safety Administration (NHTSA) on all matters related to the Theta engine recall initiative," Kia said in an emailed statement.