OK so I have been working on this k5 for a bit now and after finally getting most of the problems out of the engine she ran good for a bit, then took her on a 30 mile trip, all freeway which did really good needless to say, well the next day I started her up and noticed a tick coming from the left side, so I checked the oil and it was a little low, added a bit thinking that maybe it ram dry but that didn't fix it, so I pulled the valve cover off and poured a little oil on the lifters to see if that would work and no change, I ended up locating the ticking lifter it's the third one and noticed it was a little loose so I tightened it slowly and the ticking stopped, well the next day I drove it to work and and on my way home I noticed the tick, I could hear it over the engine and it got faster as I accelerated so I get home and pull the cover off and notice that it's lose again so I do that same thing and tighten it slowly til it stopped, well I shut it off to put the cover back on an when I start it up, it started ticking again so I gave up for the night, and started doing research and it does seem like maybe the lobe on the cam might be flattened? But also could be the stud backing out or the nut backing off? When I watched the lifters they seemed to operate normally and didn't seem to look as though it's flattened? I'm not sure where to start and would like some more opinions on the matter, I have never really messed with the valve train and on know what I have read and Been told