What's causing this ticking noise?
 

The past couple days I've been noticing a ticking noise coming from the passenger side of my motor. Inside the car, it is only noticeable under acceleration, but looking under the hood I can hear it at idle. From what I've gathered from searching, I believe it to be the plugs, injectors, or maybe a misaligned/stuck valve. I am hoping it is just a loose spark plug, but can anyone verify what it is?

Here's a crappy iphone video trying to capture the sound:

http://www.youtube.com/watch?v=JBBT76X4NYw

If it helps at all I have Altered Atmosphere fuel rails, RC Racing 650cc injectors, and NGK Iridium plugs. I'd appreciate any insight.

woh. hard to tell.

Sounds like my car did. Possible bad cam gear. I should know for sure when I get the front timing cover off. Is it loudest at cold start and the gets quieter after a second or two? It seems to get more quiet as the revs go up, that is what mine did. Sounded like a tractor at idle.

It is also possible that its an exhaust leak at the header. If so, the ticking would get faster and slower with the revs. It may also go away when the engine heats the gasket enough to seal and then come back after the car sits for a bit.

Almost sounds like an exhaust leak on/near the header. Do you smell exhaust under the hood especially on that side?

Sounds like an exhuast leak but its hard to tell from the vid. Get yourself an automotive stethascope and listen to see where its coming from.

Also, I just noticed a metallic sound on decel around 1200 rpms.

It's consistent at all times during idle, but definitely gets louder as the revs increase. I ran the car for about 10 minutes and took it for a short drive and afterwords it was still there.
Sometimes yes and sometimes no. I also believe there is a slight power loss, unless its the placebo effect.
I picked one up and the loudest ticking I can find is the fuel rails/injectors. It seems like that's the cause right now. It rapidly got about 20 degrees warmer here and that's when I noticed the ticking. Could that have anything to do with it? I forgot to check the headers with the stethoscope but I will go do that.

I agree it sounds like an exhaust leak. Also sounds like you have a slight miss. I guess a loose plug could also make a noise like that, allowing compression to squeak buy. Exhaust leak or loose plug one of the two.