2001 Galant GTZ Making loud, chattering/rattling noise. Please advise.
 

I have a 2001 Galant GTZ with a 3.0L V6, and last year it started making a really loud noise, and I just bought a house, so I didn't want to mess with it and left it sitting since. Yesterday, I decided it was time to get this car moving and hopefully not just to my other driveway. Well, I read some things, and tried some things, but not sure that it helped at all, so here is a video of the issue I am having. [url="https://youtu.be/-SDUKZHteIc"]2001 Mitsubishi Galant GTZ 3.0L V6 what is this nose? Lifters? Water Pump? Timing Belt?
My car, when in idle, makes this extremely loud noise, almost like a tick, but really really loud. It has had an oil leak, from where, I am not sure, as you can tell in the video, the oil went everywhere, and I could never find where it was leaking from, and my motor is splattered in it.
When I popped the hood yesterday, I checked to oil, and there was almost 3 quarts too much oil in it??? I didn't understand that, so did a complete oil and filter change, it filled the whole 7 quart drain pan, and then added 3 quarts 5w-30, hoping that's what I should use, and a quart of Marvel Mystery Oil, and the noise never did quiet down or go away after running for half-hour or so. When the RPM reaches 2500 or so, the noise seems to quiet some, but doesn't fully go away. Can anyone tell me what this noise is? I bought the car for my son, had it about 6 months before it did this, and haven't really driven it since. I know the battery is dead, and connectors gunked up, but I just want to know what this noise is!!! Any help is appreciated, here is the video again:

you ever find out the noise? mine does the same thing but its very faint, its pretty annyoing noise though, ide like to know what it is too, i thought it was the fuel injectors but i changed them and the noise is still there.

Never did get any replies, and haven't taken to the shop, the noise didn't go away, someone on YouTube said bad lifter(s) but not sure

i guess it was the lifters, when i went to change the valve cover gasket i cleaned the lifters and the noise seems to have went away, not sure how long it will last, maybe i should of just replaced the lifters, but i tried to be cheap, lol, anyways i just wanted to verify that i cant hear the " ticking " noise anymore after the valve adjustment and cleaning the lifters.