Q: My truck has a loud ticking sound sometimes goes away when warm.

Hello, What you are describing sounds like the noise associated with hydraulic lifters which are a part of the valve train. In the mornings or when the engine is cold, the oil has had the chance, due to gravity to drain out of these back down into the oil pan. When you start the engine when it is cold, this can produce a ticking sound as you describe. This happens as the lifters are moving without oil initially. As the engine warms up and oil circulates back up to the top of the motor where the lifters are and they begin to pump up full of oil, the ticking sound should become lighter and eventually go away. I would recommend getting a fresh oil change which should help clear this up. Fresh oil will help remove any sludge that may also contribute to any potential lack of oil circulation. Use the sound as a guide for future oil changes and if this does not clear up or gets any worse, this could be something to be concerned about and should be looked at by a mechanic.