I was browsing you tube and come across this video that has an engine making the exact same sounds as mine. Is this the cam phaser knock everyone talks about? Mine engine isn't as loud as this one but the noise is the same.

<iframe width="420" height="315" src="http://www.youtube.com/embed/3NvSRAhj0Ag" frameborder="0" allowfullscreen></iframe>

 

Yeah that sounds like it to me but I have only heard it once before.