Lifter tick or cracked exhausted manifold

Hey y’all. So in the video it was a cold start on a cold morning. The noise quiets down significantly after the engine warms up. It’s still audible but much quieter. The noise gets a bit louder and much more rapid when accelerating.

I paid a shop a few bucks to throw up on a lift so we could get underneath and neither my or the mechanic could find a crack. Also threw in some seafoam to see if we could see smoke, but no luck. So if there is a crack, it must be where the header is attached.

My other guess is a lifter tick. I’m gonna try putting in some thicker oil to see if that makes any difference. Would love opinion/suggestions on oils or additives to try.

Flexplate has also been checked and is not the culprit.

Noise.

You don't need thicker oil to fix lifter tap...throw a quart of marvels mystery oil...mmo into your oil. In 20 to 30 days it will be gone if its a stuck or clogged lifter. All 4.0 tic / rattle/ clunk and make any other sound imagineable...there is a lot of mechanical monkey motion in those motors..if you can't hear it, its not running

to detect any possible exhaust leak, what I do is position myself ready under the car.

Have an assistant start the ignition

You have maybe 10-20secs to move your bare hand close over the suspect areas before any small leak of exhaust gas gets too hot and will burn you

anything bigger than small leak will make an audible noise that close

You only get one shot at this technique, as the engine must be dead cold,

only in those first few seconds will the gas not be too hot to risk serious burns