The other recall covers nearly 187,000 2019 and 2020 Elantras, and 2019 through 2021 Konas and Velosters. All have 2-liter engines.
The piston rings may not have been properly heat-treated, which can cause engine damage, oil leaks and possible fires. Hyundai says the rings can be too hard and can be chipped, scuffing the engine cylinder. The piston problem has caused five fires but no injuries, according to documents.
Dealers will inspect and replace the engine if necessary. They'll also install piston noise sensing software. Owners will be notified in late June.
Engine failure and fire problems at Hyundai and affiliated Korean automaker Kia have plagued the companies for more than five years, affecting the owners of more than 8 million vehicles.