Well, I'm not really sure it's my lifters. It's a little louder than a ticking sound

https://www.youtube.com/watch?v=6sHaNn6XRVc.
If that noise you hear is more of a clack-clack than a tick-tick, you could possibly have a spun bearing.

Spun bearings are when the rod or main bearing spin with the rod cap/crank journal. the bearings are crescent shaped pieces of metal. (Bearing Image ) when there isn't enough oil to supply the space between the crank journal and the rod bearing/main bearing or the crank journal and the main cap the bearing will seize on the crank and follow it's rotation. This is bad for multiple reasons. the most obvious of which would be the metal shavings from the bearings as they spin in the rod cap without oil or the main cap without oil.

As an added thought, if it is louder than a tick, you may have a rocker arm that's popped off. It is quick and easy to check (compared to a spun bearing anyhow) by just pulling the valve covers. Obviously very serious damage can result such as tearing up camshafts, sending metal through out the engine, damaging valve springs, etc.

Spun bearings are waaay easier to diagnose than a thrown rocker arm.

Step 1: Remove oil filter.

Step 2: Cut it open and look for a pot o gold.

Jeff

My experience of a failed big-end bearing in a NA DOHC V6 Mitsubishi 6G72 engine:
1) It happened very suddenly & without any warning at about 170,000 Km.
2) The noise was really loud, almost like being in WWII next to a Vickers machine Gun.
I don't know how unique this was or wasn't?