Hi Scotty, I have  a 2010 Ford F150 4x4 5.4 auto transmission with 99,000 miles. No check engine light or codes that I am aware of, but I haven't had a scanner hooked up to it. I have a rattling noise in the engine compartment. The local Ford dealership said that it's the fuel injectors making the tapping noise. I have been researching this online and it looks like the 5.4 3valve engine has a common issue with "roller follower tick" and "camshaft phaser knock".  How can I know for sure what issue this is?  If it is the roller follower issue, I'm under the impression that it will eventually cause some major engine damage. It would be worth the drive from central Kentucky if you would be available to check it out.  Thanks for your help.