Got the same problem. My 2004 just turned 100K and I've noticed the problem more now that the mornings are colder. But even as my engine warms up, noise is not going away. I run synthetic oil exclusively and the levels are normal. Have been told that it might be an item relating to the timing chain. Some sort of adjustment maybe.
I just posted this problem also. I don't see that you have received any answers.
o. Buckeyes@yahoo. Com
Wednesday, November 28th, 2007 AT 9:09 PM