On the 2.7L V6 and 2.4L 4 Cylinder, a defective exhaust gas recirculation (EGR) switching valve may cause an intermittent rough or unstable idle engine.
2006 Hyundai Sonata Problem Reports
Most Reported 2006 Hyundai Sonata Problem Reports
Problems with the accelerator pedal position switch may cause the Check Engine Light to illuminate; an improved switch is available to fix this problem.
If you experience excessive engine noise on startup (after the engine has been turned off for several hours) that lasts for more than five or six seconds, turn off the engine and check that the engine oil level is correct. If the oil level is correct, the noise may be caused by the timing chain tensioner. Hyundai has an improved tensioner to correct this problem.
Parking lights not turning off intermittently or all the time. The common problem is with the cabin fuse box. Complete replacement of the assembly is necessary to fix the problem.
If the automatic transmission does not shift properly and the Check Engine Light illuminates, the speed sensors in the transmission may have failed. The sensors are simple and inexpensive to replace.
The motorized seat belt may chatter or become jammed in its track and not operate properly; Hyundai issued a recall for 1990 - 1994 model years that should correct this concern.
Prior to replacing the automatic transmission fluid (to improve shift quality), make sure that the transmission fluid level is correct. Also, make sure the computer that controls the transmission has the most up-to-date adaptive programming information. When servicing these transmissions be sure to use fluid approved by Hyundai.
The problem Im having with my 2007 Sonata is the paint is peeling off like nail polish. And rusting on the hood near the wiper blades. Squiking front end during cold weather.