One problem related to cooling fan has been reported for the 2008 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Hyundai Sonata based on all problems reported for the 2008 Sonata.
While driving the seat belt light came on. About a minute later the radio shut off. Next most of the dash lights came on , the engine would not make power/accelerate, and the braking seemed weak/jerky. Pulled into a parking lot as soon as I could. Now all dash lights were on/blinking and the radio, sunroof, windows etc would not work. Thinking it was an electrical issue I left it running to investigate. Next thing I know the car is overheating even though the gauge isn't showing it. Steam everywhere and the overflow popped the cap off. Shut the car off. Once the car cooled I was able to see what happened. Oil has been dripping on to the alternator from a leak in the valve cover gasket. This killed the alternator which in turn caused the control/braking/acceleration issues one it was on battery only. I'm assuming the fan was not cooling either which resulted in the overheating.