What kind of oil do you use and how many miles/kms? Sounds like an exhaust leak to me, but could be starting of phaser knock which isn't really an issue of oil pressure is good.

 

5w-20 Mobil 1, truck has 188k miles. It does have an exhaust leak on the passenger side that seems to mostly quiet down a little while after it’s started. The phasers have been locked out, and all the timing components were replaced 30k miles ago.

 

Switch to 5w30 Penzoil Platinum high mileage and change every 5000 miles is the first thing I'd do. And most use the motorcraft filters, but lot's of posts about them not being good quality lately. Now we're timing parts all Ford parts or aftermarket? If phasers are OEM then your knock is most likely just an exhaust manifold leak, but is phasers are aftermarket then you could very well have the an issue with them.

 

previous owner replaced all the timing components, but I have the receipts. I checked the part numbers and all the parts were cloyes brand.

 

Is noise greater in front of engine?

 

no not really, I can hear it from both sides and the front as well. Seems to go away once rpm’s are raised.

 

Phaser knock doesn’t happen with good oil pressure. I don’t mean “good” as in Ford’s revised lower spec (15 psi?) to get people to go away, either.

Phaser lockouts, eh? That tells me the PO did a cheap bandaid fix and you’re about to rip that bandaid off in a real expensive way. Wear from low oil pressure won’t stop just because of the lockouts. Now you get to figure out what’s worn out.

 

well shoot, that’s not really what I wanted to hear.
The truck runs perfectly just makes that noise at idle.guess I better get in there before something catastrophically fails. Thanks

 

If the phasers are locked out you probably have nothing to worry about as far as that noise is concerned. That sounds like the hot idle phaser knock, but locked or unlocked it's more of a nuisance than anything
as long as you don't have chain rattle or cam followers tapping you should be good.
As suggested run a thicker oil 5w30 minimum. Xw20 is too thin for this motor for the vast majority of us with normal or especially worn clearances.