engine noise ?

[Fox]

i'm getting a strange engine noise from 2500 to around 3500 rpm alot more noticeable when driving, not sure how to describe it, it's kinda a rattle i guess, if i hold it around that rpm it is always the same and doesn't change once past that range its fine

you can sorta hear it in this video, i have no idea what it might be :confused2:
at 0:28
http://www.youtube.com/watch?v=NLPgb4T08MI

[BadAssPerformance]

*didn't see the video yet*

In every gear or more noticeable in some?

[Fox]

its in every gear

[shadow88]

Something loose on the engine like a bracket or pulley? The braces from the engine to transmission, or alternator mounting points or water pump pulley bolts, or exhaust heat sheilds, or the firewall heat sheild? I can't make anything out from the video.