Did you change the timing chains on your 4.0 SOHC for maintenance?

[morsetaper2]

If you are asking, I am betting you have not heard it... there are hundreds if not a 1000 youtube videos on it. Here's what I would do to double check, take the serpent belt off to eliminate any belt driven noises, and then compare it to this guy's noise from 0:54 to 1:22

I was looking at things yesterday and did look at the serpentine belt. I think it's ready to be replaced. About to hit 190,000 miles on the OE belt. So I will do as suggested to check noise w/ serpentine off. But as you suggested, at this point I have nothing even remotely resembling the rattle that the youtuber's Explorer is experiencing. So at this point my engine is good.

Going to change out the external F & R tensioners when I fix the leaking thermo housing here later this week. Ordered a housing from Simmons Autosportz today. Going to start gathering all the other parts reqd to replace serpentine belt, tensioners, and the thermostat housing. And while I am through that passenger side wheelwell, new spark plugs need to be installed.