Noisy startup when cold, sounds like valve

Hello onarock844...The Hyundai 2.4 litre and the 3.3 litre are known to have valve train noise. Some sooner than others.
The timing chain tensioners on the 06 and 07 Sonata 3.3 engines built before August 4, 2006 are well known for developing wear that allows them to make a tapping or rattling noise for a short time after a cold start. This noise can be mistaken for a lifter noise, although the actual source is in the front cover area of the engine. Hyundai has released a technical service bulletin on this problem, which describes installation of an updated design timing chain tensioner (part #24410-3C300) to correct this noise issue.
Ask your dealer to refer to Hyundai service bulletin #06-20-002 for information...If this has already been corrected,,,and the noise is coming from the upper engine area and not from the timing chain area, then the valve clearance will need to be adjusted. This is done by disassembling the valve train and installing slightly different size tappets to change clearance.
This is a fairly labor intensive process, so if you are still under factory warranty then you will want to go over the dealer's head and get the Hyundai zone rep involved to get it covered before your warranty coverage expires...
I recommend useing a full synthetic engine oil, i know in a few cases where the noise has stopped when the oil was changed over to synthenic, also a high quality filter is important, such as a purolator.
Good luck...i hope this helps...please rate me a fixya.