Its a little late, but if you are mechanically inclined you can service the valve train and almost completely get rid of that noise. Given that its an 04 its probably time for valve lash adjustment. About a year ago I noticed that my truck sounded like a diesel after I put an exhaust on it, and I mean like a diesel. If you closed your eyes you would have thought you were under a duramax. I pulled the valve covers and took a peak at the rockers and was blown away. I've seen some **** when I was working on diesels, but I would have never believed that a gas engine could be that far out of spec and not kill itself. I could almost fit an 1/8in drill bit between the rocker and roller, no wonder it sounded like a diesel, that thing was hammering away for who know how long, i'd only owned it for about a year at that point.
After servicing the valve train (I had to pull the rockers on that side so I could lightly sand down the impact marks) you could barely hear the valves with your head right next to the covers.
Otherwise, you can either switch to thicker oil, or mix in thicker oil until it quiets down to where you like. Until it starts sounding like a diesel, vavle noise isnt much to worry about.