One problem related to radiator has been reported for the 2012 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Hyundai Sonata based on all problems reported for the 2012 Sonata.
Recalled engine replaced in late 2017 car continues to have problems every since. Had to replaced water pump , thermostat and 3 radiators and was told that the head gasket is blown. Hyundai dealer and service refuse to correct the issue and I have spend over $2,000 in repairs.