im confused. I'm not sure if its a "knock" or not, but i just up and appeared out of nowhere. Wasn't like that when I garaged her back in the fall. I don't think it's the lifters, but I am going to do an oil change later today and see what happens. I will take your suggestion and tighten all of these connections (if lose) and fill her up with a full tank of fresh gas once it runs out. Thanks for your advice