05, z71, 5.3, engine making a knocking sound

[Luke05z71]

I have a 2005 4x4 chevrolet tahoe with aprox 185k on it. My engine has started making a knocking sound after running for a little bit. I put a heavier fully synthetic mobile1 oil weight in it along with the Lucas oil stabilizer, and it doesn't really make a difference. Currently, there's no engine light on. Everything is stock with the exception of a small leveling kit.

 

[jcy110]

My 2001 5.3L does the same thing.......I warm it up all the time before driving wait until it gets quiet. 235,000 miles...........still rides like new!

 

[PNW NBS Z71]

Does the knocking sound change at all with rpm? Is it a knock sound or a tick sound. Don't forget that the exhaust manifold studs/bolts break at the ends on these engines and the exhaust leak can sound like a knock/tick.