Well I bought a used 2006 Sonata 6 months ago I really loved it in the beginning until 3 months ago when I started my car there was a noise it sounded like something was grinding. I took it to the dealer they said it was normal, they could do a oil change and that should quiet the noise. The noise got louder. they called in the regional inspector to listen to it. Well he came in and listened to it and now I am being told this is a normal noise, that I now have to deal with because there is no mechanical problem according to them. They call it a "characteristic" and since there is no mechanical failure they will not correct the problem. Although the car never made the noise when I bought it. I bought a new car to have it not sound like a piece of junk, the looks I get when starting a very nice car is like WOW what a piece of junk. The 2005 to 2008 Sonata's all make this noise, so I am being told now. So needless to say I will be down at the dealer this weekend asking them how much they will give me for my car that sounds like the engine is going to blow any minute when I start it. I know for sure I can't get top retail value for it, as soon as I start the car for an interested buyer and they hear that noise and I tell them this is normal and I have a piece of paper that states this is normal for this car they will laugh in my face and walk away. I am now stuck with a $14,000.00 car that the value I am sure just decreased buy $10,000.00. I wonder how this engine was able to be tested and pass inspection on the production line at the plant and make it in the vehicles without this being disclosed to the unsuspected buyer. I would like to hear from anyone with a 2005 to 2008 Sonata V6 who is currently having or had this problem. With this piece of paper I am being told if there is mechanical failure with the timing chain or tension pulley they will fix it as long as it is within the warranty period. I am sure the problem won't arise until 100,000 miles just as the warranty runs out.

I've had the timing chain tensioner replaced on mine (under warranty), The noise was gone for a while, but now it's back--I assume to the faulty design (no catch on the tensioner).

That or it can be the HLA's. I'm just living with it right now..