Two problems related to engine belts and pulleys have 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.
Was heading to work on interstate 81, engine made loud boom sound scared me pulled over being afraid to drive had it towed to an auto repair shop. No engine light on. Repair done a diagnostic test said engine was blown, oll good no engine light but engine wouldn't turn over trying to do manually. My car only had 180,000 miles always did belts and maintenance.
Upon starting the car, I heard a high-pitched whine from the engine that increased in volume and intensity as I accelerated (in town), and then I observed two puffs of smoke or steam arise from under the front of the hood. I immediately stopped at a nearby mechanic, who observed that the front cylinder bank valve cover was leaking oil. The whine, which gradually went away, may have been oil getting onto the alternator belt. Fortunately, we seem to have caught this in time, as the alternator did not appear to be damaged, but it easily could have been, as the edge of the valve cover hangs directly over the alternator in the 3. 3l v6 engine. The leak may have been more of a "sweat" for an undetermined amount of time; only the whine alerted me to anything being wrong, and may have been a sign the leak was getting worse over time. The mechanic replaced the valve cover gasket. What is frustrating is that Hyundai has issued a recall for this same problem, on the very same engine I believe, for their vera cruz models, but not their Sonatas for the same years. They should recall the Sonatas with this engine as well, as the alternator can be destroyed if this isn't caught and fixed.