 These cars had engines with faulty timing chain tensioners; they can fail with no warning and cause severe engine damage. My Mom's 07 Sonata had 127,000 miles and had a timing chain slip, causing cylinder head damage.  Hyundai has been sued for the 2010-2011 models (for the exact same problem), why they got away with the 2006-2009 models is a crime. If you complain to Hyundai, they either ignore you or try and sell you another POS Hyundai. Stay away from these junk heaps.