1999 LS Clicking (engine)?

Recently I've been hearing a very prominent slurping/spongey click. Does 1-4 slurpey clicks and stops for a bit. My uneducated guess would be something with a pump/lifter is the problem but I really have no clue. It sounds like it is in the dashboard, but it only happens when the engine is running so I'm guessing it's not electronics in the dash.

Most prevalent when I first start the car, idle and parked. It has nothing to due with turning or anything like that. That said, I can sometimes hear it when I'm cruising on the highway. It is loud enough to cause me to worry, but I haven't noticed any performance issues.

Any advice on where to start looking?

P.S. It has been taking a few more ticks from the starter to fire up than normal lately, but that might just be because the battery is aging a bit and it's getting quite a bit colder here quickly. Probably unrelated... just giving any hints I can.

Thanks

EDIT: I think I solved my own problem and I'll share my negligence here so hopefully someone else can solve the same issue. The oil level was right on the "add" line. Last time I check the oil it was hot, this time it was cold and gave me a more accurate reading. I've had a few other fuel type issues with this car but I haven't lost significant oil in this car before so it took a few minutes for that to cross my mind. I added 3/4 of a quart of oil and as of right now the noise is gone...I'll update if this wasn't the issue.

Good luck!