One problem related to engine failure has been reported for the 2001 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 Hyundai Sonata based on all problems reported for the 2001 Sonata.
Engine failed at 1633 miles going 65 mph on major highway. According to hyndai service there is a problem with engine sleeves in early production engines. Sleeves come loose causing pistons to smash spark plugs. New engine installed, but did not run properly. Hyundai service ordering second new engine. Problem diagnosed quickly due to another 2001 santa fe with 3900 miles in shop with same problem. Peoples Hyundai in folsom, CA were very helpful.