Ok here's the deal. I've heard alot of people talking about a ticking noise coming from their 04'-08's and it always seems to be the cam phasers. Well I have a similar problem but in my 02' Ford F150 5.4L. It is a very annoying ticking noise coming from the topside of the drivers side of the engine. It hasn't affected my power but it is annoying as hell. I understand my truck doesn't have the cam phasers. I have checked all kinds of things. I've been told to check plugs, coil packs, injectors, manifold gaskets. I have changed the plugs and the coil packs are all good. I have yet to change injectors but before I go doing that I was wanting some thoughts on what else this noise could be. It made the noise with stock manifolds so I figured instead of changing the gaskets I'd just go with aftermarket headers. Installed the headers, fired it up, the ticking continued. Like I said it's not hurting me so far as I can tell but I don't want this to affect me in the long run. Any thoughts, info, or past experiences would be awesome. Thanks in advance Jack.

 

Injectors can be noisy, might be your problem.