Two problems related to radiator have 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.
The engine consumes extraordinary amounts of engine oil. At 72,000 miles, over 70% of engine oil is lost between an oil change range of 7500 miles. Radiator fluid levels drop as well. I believe the engine has internal problems that lead to engine oil and radiator fluid to enter the combustion chamber. This has been the case since very early days and was also reported to us by other service centers. It has gotten worse over time.
Takata recall. . . . . . I was driving my car and I heard a loud noise, shortly thereafter, the car dashboard said that the car was running hot and it shut down in the middle of traffic. I rolled to a stop and put the car in park. I got out the car and look under the car to see if I saw anything because of the noise, and I didn't see anything. I popped the hood and noticed that the antifreeze level was not low and that the pressure was not tight on the radiator hose. So I could not understand why the car was running hot. I closed the hood and got back into the car and started the car back up because it appeared to have cool down. I drove the car to the nearest parking lot and called a tow truck to take the car to the dealership. Once the dealership look at the car, they noticed that the pulley was not on the alternator, the serpentine belt was at the bottom of the car and that was the reason the car was running hot. They said they have never seen anything like that before. New car with only 66,000 miles on it and the pulley on the alternator is completely off while driving is not safe. In rush hour traffic in the city, is not safe for me and my kids.