not really the greatest video done with my phone but the secound rev u can hear it like a ratteling sound any ideas of what it could be link below

http://www.youtube.com/watch?v=Nazf_zig4sw

 

Sounds like the timming chains or the chain guides. I would have it looked at very soon. Sorry

 

Kinda sounds how a catalytic converter sounds if it goes bad. I don't know that it would be your timing chains, but its possible i guess. Sounds to me like a bad converter, especially since when you rev it it gets louder. If you have an x/h pipe without converters then your converters obviously isn't the problem. Hard to tell from the video....

 

I have a rattly cat and it sounds nothing like that (then again, it's not the best of quality video). If you want to check if it's you cat, tap them (lightly) and see if you hear a rattle.

 

I hear it faintly but it can be a spun bearing,exhaust leak, alternator or something on drive system with bad bearings or valve train. Its something you need several people to look at. Go under the car and listing there to see if it sounds louder.

 

Good call. I had an exhaust leak and it sounded similar to that, but not quite that loud.

 

sounds like valve tap try running some castarol syntech in it it might go away

 

Running a different brand of oil won't do anything but running a different grade will. Even then, running a thicker grade is for worn engines since the clearances get larger and if the grade is stock 5W-20, this noise would only be due to a part going bad, not a different brand of oil.