My trucks a 2006 4.7 1500
with 330000KM

its been making knock knock sounds in the morning or first starts

here’s all the issues incase I’m over looking something

-when warmed up the knock goes away or gets quieter,

-the exhaust is pretty rusty with holes in muffler

-more loud under the truck then top of engine

- there is no power loss at all

-every 1/15 times I start it, it just cranks and doesn’t start right away. (unless I let it prime aka fuel pump?)

I got a video of sound

https://youtube.com/shorts/qp8sYYyJguA?feature=share

I don’t think it’s rod knock because it should be getting louder with revs
I had a 06 ford with cam phasers that sounded like this so maybe it needs new timing chain?


i dunno I’m not a mechanic but I can replace parts.

 

Sounds like worn main bearings.