Lets see if the op shows back up after 2 years, but to me his video sounds just like the exhaust leak my previous truck had. It would go away after about 30 seconds after starting the truck. It had headers on it and it was a leak between the header and the block.

 

That's exactly what my truck does... Passenger side exhaust manifold.

 

2004 with 140,000 miles. Had passenger side exhaust manifold replaced two years ago. ($1000.00) Cracked again one year later. Replaced under parts warranty no cost. Now ticking again. Cold starts you hear it. Once it warms up gets pretty quiet, unless under load. Other theories from various sources. Warped head, manifold will always be compromised? Air conditioner drips on manifold causing issues? Poorly engineered engine? The venerable 5.4 triton. I am considering either a pickup replacement or rebuilt engine in this one.