Engine Noise

[blkexp98]

I have a 2007 V8 and when i accelerate fast i get a fast tapping sound. I think i remember from my explorer that is the valves. So with that said what causes is and what do i need to do? I have about 23K miles on the 4Runner so its hardly broken in by toyota standards. I also run midgrade fuel and have tried a few different stations.

Thanks for any help,

Major