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.Google+
Car Problem Reports
Hyundai Sonata Improved Timing Chain Tensioners Available to Correct Noise on Startup
Hyundai Sonata Problem
Engines Affected: 2.4L 4 Cylinder, 3.3L V6
Average Mileage: 77,082 mi (20,000 mi - 132,000 mi)
Visitor, 2006 Hyundai Sonata, 3.3L V6, 29,000 mi
This strange noisy gremlin began in April of 2013. At first it would not happen every time on start up
(after sitting overnight) and was initially 2 seconds. By August the rattling noise was happening more
regularly on start up.........and slightly longer in duration........but never after restarting a warm engine. In April I spoke to a Hyundai service manager who informed the timing chain tensioner was known for creating this problem and Hyundai redesigned the part. In August I spoke to the same person and he volunteered the following information. I found it hard to believe he claimed he NEVER replaced timing chain tensioners, unless it was to correct work done by the "corner repair shops", implying they screwed things up. Specifically, he said do not be concerned with a 2, 4 or 6 second rattle upon start up. Really? I am a perfectionist and expect a manufacturer to do the right thing, i.e., make a GOOD CAR and/or replace defective parts. We were the second owner and got shafted by Hyundai's self serving limited warranty of 5 yrs/60,000. Of course what good is any warranty (new or used) if the dealer gives you the runaround. This service manager claimed there is not need to be concerned unless the chain rattles for 90 seconds on start up, or rattles once again after the car is restarted after 10 minutes of sitting. Additionally, when asked about worst case scenario he said the CHECK ENGINE will come on at the point the issue is preventing the car from running properly. This will most likely be our FIRST and LAST Hyundai product. Although they are not the first to dump a poorly designed product on hapless consumers, I desire a car maker who owns-up and makes things right. While some so-called mechanics theorize this problem arises from pool maintenance (infrequent oil changes) the fact remains the part was REDESIGNED, which clearly implies otherwise.
Visitor, 2006 Hyundai Sonata, 3.3L V6, 40,000 mi
Our 2006 Sonata with 3.3 L engine has been makiing this noise for over a year. Was told last year that it had to make the noise for longer than 15 seconds before they fixed it. Did my own oil change last fall and found a lot shiny metal particals in drain pan. Mentioned this to dealer in December and was told the same thing as last year. Contacted Hyundai direct and was told it should be fixed as it is "under warranty". Taking it to dealer this Thursday (1/24) for them to check it out. We'll see what they say then.
Visitor, 2010 Hyundai Sonata, 2.4L 4 Cylinder, 63,000 mi
Timing chain tensioner noise since 20k miles, took in dealer said 'normal'. Now it is much worse, taking it back and going to insist on the tensioner being replaced under my extended warranty. Is there any TSB number or document I can print out for the dealer to deflect the standard 'I don't want to do it' crap?
Visitor, 2006 Hyundai Sonata, 3.3L V6, 101,000 mi
I purchased a used 2006 Sonata 2 years ago. It has been a great car until recently. For some reason it has started to occasionally make a rattling sound when I start it. The sound is coming from the area where the belts are located. I have read that other owners have traced the problem to the timing chain tensioners. I have called the local dealer service department but they are not very familiar with this being a problem. :( Scared to find out what they will charge to fix the problem...
mine is doing the same thing aqnd its going to cost me 1200 dollars
Visitor, 2006 Hyundai Sonata, 2.4L 4 Cylinder, 132,000 mi
knocking sound on engine area, sounds like tming chain of lifters.
Visitor, 2008 Hyundai Sonata, 3.3L V6, 124,000 mi
Timing belt tensor broke and caused damage
Rattle for about 10 seconds after cold sturt up and every start after sitting for 10 minutes or long.
Visitor, 2007 Hyundai Sonata, 2.4L 4 Cylinder, 126,000 mi
Still working on it
Visitor, 2006 Hyundai Sonata, 3.3L V6, 74,433 mi
excessive engine noise on startup