Two problems related to engine cooling system have been reported for the 2009 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Hyundai Sonata based on all problems reported for the 2009 Sonata.
Purchased a 2009 Sonata in spetember of 2008, the air conditioner does not drain and has developed a mold smell when air is on. Returned to dealer, they want to "clean" evaporator with a foam cleaner at a cost of over $100. 00. The tech said to drive car in the outside air circulator and not the recycle air engaged, since I refused the "cleansing". This making me sick, friend has a 2009 santa fe with same issue.
New car was delivered to me with a major engine oil leak. Could have resulted in engine failure and loss of control. Engine was replaced but has caused power train vibration and strong odor when the engine is warm.