217K. Sounds like lifters tapping when the engine is under load even when warm. Just started a couple days ago on a cold morning (15F). I also noticed that the typical oil pressure light that normally stays on until the engine warms up (faulty sending unit) does not come on at all when the engine is cold. (it still lights up on the panel at startup check) Just got back from a 2500mi trip at highway speeds and had the oil changed just prior to the trip.
Does anyone have any insight on the issue.

 

had similar on my 97 f150 4.6. When I had someone step on gas I listened for tick. Found it to be a broken exhaust manifold bolt which in turn caused a leak.Possibly this might be what you have. Go to harbor freight for under $5 buy a auto stethescope and listen to isolate.You can also put ear to a broom stick or screwdriver. Tough to get manifold off and replace bolts and manifold but still better than an internal problem. Hope you get lucky and its only minor

 

I will try to isolate the noise, thanks for the input.

 

sounds like exhaust leak.