I was just driving to work, and when I pushed on the gas pedal this sound started. Here's a link to a video of the noise: https://youtu.be/5hAQkXJq11o
Any information as to what might be causing it would be appreciated.
Sounds like a rod knock.....perhaps your rod bearings are going bad. Lots of youtube videos' on rod/bearing knock. You could start pulling plug wires to try and isolate which rod is failing if that makes you feel better. Regardless.... looks/sounds like 4age rebuild time. BTW, No point in half assed rebuilds on these engines, you either do it right the first time, or do not do it at all. Properly taken care of, a 4age should go approx 300,000 miles. Good luck and you can always consider one of many engine swaps if you are so inclined.
Besides rods or valve possibilities, a loose cam gear sounds just like that. Once loose their shaft interface is quickly damaged and it will need to be replaced. Easy to check and fix and certainly worth investigating before tearing open the engine or head.
This occurs to me because one time I had just completed swapping in a rebuilt small port and was very disappointed to hear such a noise. Loose gear. Had to replace. Has run great in a race car ever since.
It's not loud enough to be a rod banging the cylinder walls. If its rod related it's just a bearing.
If it's some chunk of valve or ring in the cylinder above the piston, a compression test should tell you. At 200K miles a compression test will be useful info anyway.