making knock sound or like mains rattle at 2000rpm or above

[ar1chris]

just bought about 5000 miles ago it had almost 93000 now has 97000
just noticed other day on highway it was making a noise at bottom of engine it was time to change oil checked it first about a quart low changed it, at first thought noise wasn't their but still is also was thinking maybe bad gas so put some octane boost in. would a knock sensor or something else make trk make this noise?

 

[ar1chris]

just bought about 5000 miles ago it had almost 93000 now has 97000
just noticed other day on highway it was making a noise at bottom of engine it was time to change oil checked it first about a quart low changed it, at first thought noise wasn't their but still is also was thinking maybe bad gas so put some octane boost in. would a knock sensor or something else make trk make this noise?

 

[Jackmldog]

Inthe words of the game show host on Billy Madison " I award you no points, and we are all dumber for having to read this." haha but seriously it could be many things. A little bit more info would help. Such as does the noise increase or get faster or slower with different speeds. When is it louder? Or is it the same all the time?