One problem related to coolant leaking has been reported for the 2015 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2015 Hyundai Sonata based on all problems reported for the 2015 Sonata.
I bought this new car a few months ago. At 1089 miles engine overheated while in traffic. I manage to stop safely and I called roadside to tow the car to service. Second day they told me that they need to replace the engine according to Hyundai tech line. This for me was a red flag that something is really wrong with that car. They found coolant inside the engine and this was their diagnosis, jsut like this. The replaced the engine with a remanufactured one and few weeks later I ended up in service again for coolant leaks. They replaced 2 big houses. Not long after this I ended up again in service cause coolant level is low on the overfill compartment. They said is nothing wrong and all the tests are good. So I took the car and a couple of weeks later the same. They told me the same story. Well the car overheated again and again and again till everything started to smell like something melted and some kind of smoke came out from inside the engine when you open the oil cap. The car has been in service for more than 3 weeks with no resolution so far. I reported coolant issues from the beginning but Hyundai refuse to listed and kept saying is nothing wrong. I consider this s huge issues and can cause the car to get on fire or engine to explode. I hope to get this done under lemon law but Hyundai is stubborn and we might end up in court. In the mean time I am paying for the 7 months for a defective problem not to mention the value after all these major issues.