I have an 05 ranger FX4 with the 3.0. I want to say it's coming from the lower end but hard to tell. Any ideas. About 145,000 miles roughly it ran low on oil and I got a tick then when I realized it I knew it had to be low or leaking I found some oil leaking down just can't find its origin yet hadn't got into it yet waiting for tomorrow. I put Lucas oil stabilizer in it thinking maybe a lifter was stuck or collapsed trying to plunge it up and maybe go away but no luck let me know yalls thoughts. Hawesville ky here

 

I also have engine light on flashing after warm and idling for about 5 minutes has really rough idle. Hooked up the computer and said #5 cylinder had a couple misfires.

 

Flash CEL is bad, it means "warning, engine damage may occur", so just FYI.

Steady CEL means "have a look when you have time, no rush"

Flashing CEL on misfire is common and not good.

"tick" and "knock" are quite different noise wise, tick could be valve train issue.

2005 3.0l is in the range of the "recessed exhaust valve seat" issue Ford had with Rangers, 2004-2006, were the year of that TSB.

And it was misfire issue that just starts one day.
Google: TSB 05-26-3

The knock could be spun connecting rod bearing, caused by overheating because oil got low.
Oil does lube the bearings but cooling them is just as important if not more so, running low means less oil in the pan cooling off.

If you can hear the Knock at idle, then pull off spark plug wire for #5, while engine is still idling, if knock goes away then it is connecting rod bearing issue.
You should actually test all the cylinders that way.

Compression test is only way to test for the TSB issue