2008 Ford F150 making ticking noise when accelerating?

I have an 08 f150 100k miles and most of the time when I accelerate it makes a ticking noise. Its not quite a rattle, or a knock, but rather like one tick over and over when i accelerate. Very rarely I can hear it when Idling, but it doesn't sound right. I have had my mechanic look at it and when i brought it in it was working fine(of course). The oil pressurse stays solid at 1/2-3/4. I got the oil changed. Went from using 87 gas to91. Used 44k fuel cleaner and that seemed to make it better for the first drive afterwards. When I first got the truck it wasn't making this noise. It ended up having a camshaft issue and they had to replace it and thats when it really started. Just looking for advise to see where to start for this one?

Added (1). It was actually the cam shaft phaser that they had to replace.

Ticking noise under acceleration, if you are not talking about engine knock, is probably going to be an exhaust leak at the manifold. It sounds very similar to a ticking lifter, but is usually only heard under acceleration. To rule out engine knock, run a tank of premium through it. If it stops, then there's probably a timing issue or, more likely, something wrong with the knock sensors.

It could be a sticky valve lifter but your mechanic should have been able to determine that. Lifters had to be removed when the cam was replaced. I would take it back to mechanic who did the cam work.