my 06 5.4 on cold start sounds like a exhaust leak , quiets as it goes from high idle to low. Still there on low idle just not as loud. Can increase rpm and it stays about the same quieter tick. Any thoughts to check appreciated. Have been told cam phaser to belt tensioner. What checks can be made? Hell maybe its an exhaust leak.

 

In my opinion, cam phasers usually have a faster tempo or shorter interval between ticks, whereas an exhaust leak has more of a "put put" sound. But it can be hard to tell the difference.

 

Take a look at the studs on the exhaust manifolds, make sure all the nuts are in place.

The cold vs. warm is because as the metal heats it moves, this can cause the issue to get worse or get better. All depends on which way the manifold wants to move.

Very easily could be an exhaust leak.

With the motor cold you can hook a shop vac (on blow) to the tail pipe and spray the suspected areas with soapy water and look for bubbles.

 

This is my exhaust manifold leak sound.