The video is only 9 seconds. Apparently I am having a lot of problems with my GT right now. It started two days after I drove from Hershey Park, PA and back (about a 100 mile trip one way). It's my DD on a 25 mile commute and I initially heard it on my way back from work. I tried going from 87 to 93 octane today and it didn't help. All of this is coming from the passenger side of the engine. The driver's side doesn't make any noises. I've been told it sounds like a lifter or a bearing and was looking for some more input. Is this going to be an easy fix to take off the valve covers and put a new lifter on? It's not a very loud knock like the lifters are too tall but it's enough to make me worry. I also have an exhaust leak lol.... This is what I get for DDing a 25 year old car.