The vehicle demonstrated in this video is a 2004 Chevrolet Silverado (GMC Sierra) and applies to all half ton pickups from 1999-2006.
However, the issue may apply to many more vehicles. I thought I had a bad case of lifter tick until I realized that it was the GM spark plug boot's funky metal shield/protector rattling against the block. I'll be torquing it so that it does not rattle anymore once the engine cools down in the morning.
This loose spark plug imitated a much more concerning issue (lifter tick or even piston slap) and I was very glad to find that re-torquing the spark plug resolved the problem.
If you find that you have a ticking noise soon after modifying/replacing your spark plugs do not jump to conclusions like I did and try to perform the "Italian Tune-Up" this could've shot the loose spark plug right out the block and thru the top of my hood.
Instead, check that your spark plug has not come loose. This was the very last spark plug on the passenger side of the engine, very close to the firewall and really hard to access, which would make sense why it was torqued less adequately than the other plugs. Once the engine cooled down, I torqued the plug another 1/5 turn and it's been fine ever since.
