http://www.youtube.com/watch?v=2Y7etgb6G8g

This only happens at idle.. past 1500 rpm it goes away. Sounds like something with the chain but not too sure. :/
Timing chain guides have been removed already with a new tensioner. Both done around 14,000 miles ago. Pulled the valve cover today and everything looked normal.. What else should I check? motor has 142k miles

sounds like the timing chain guide noise... i know you said you had them removed but it definately still sounds like the timing chain guide getting slapped.... check yur oil, i noticed that when my oil's low i get that noise a little louder then usual...

^If your oil gets low, its because its leaking or your car is drinking it. You should fix that.

Original poster, Pull your valve cover off, and remove your upper timing chain guide at the front of the engine. Its the little piece that looks like its suppose to do good, and keep the chain from rattling around... well, it sucks.

If the problem still persists, there is another upper timing guide on the passenger side of the engine, near the top just under the intake cam sprocket that is also known to make noise.