Knock knock

[chefkrewtonz]

I apologize if this has been posted before. I scrolled and scrolled.
But, Everyone in here is far more intelligent than I am. Can anyone tell me what might be making this knocking sound? I can't imagine it's a good thing, and l'd like to get it taken care of asap.

She's a 16 ST that just crested the 100k mile mark.

Thanks in advance.

 

[chefkrewtonz]

Just some additional info, no loss of power, or change in drive ability. The knock does get faster as the acceleration increases. From my little knowledge, I think it might be the High Pressure Fuel Valve, heard they tend to expire around the mileage I have.