I heard a loud noises from engine like tappet or valves starting cold. I went to Sonata dealer. They checked it out but could not find anything to report. Today again when started the engine did not make that loud noise only the tappet/valves are still clacking until driven a few 100 feet. Then it's quiet operating normally. I asked the Sonata serv. rep. if the could check the codes but they said it would not show up. I did read one paragraph in repairpal that stated it could be the timing belt tenshioner. I have 58,269 miles and the both belts were changed because of this year model -last one from North Korea & not Alabama.
What can cause tappent/valve noises upon starting cold but go away when warmed? on 2005 Hyundai Sonata
by bluewilly in Palm Harbor, FL on November 25, 2012