hi, New here
I recently purchased a 2010 f150 5.4 xl. with 64000 miles
I love the truck, had it about a month now. about a week ago, it started making the dreaded diesel sound. over the last two weeks, it has gotten louder. it only does it when in gear around 1100-1800rpms. took it to my mechanic, sure enough, cam phaser on the passenger side. he told me it's a common problem with these trucks. and that it's ok to drive it. he offered to replace phasers, but said in a few thousand miles it will likely come back. he had another truck in for the same problem.
instead of replacing phasers, he told me to give him a week, that he was trying something new on this truck. he's gonna install a cam phaser lockout. that'll be the first one he's put a lockout in so he wasn't sure if it would fix the noise issue or not. the other truck was much louder than mine.
I've done a lot of research on cam phasers lockout.I see where some have tried it, but not their feedback on results.

My question is, do I need a lockout, or just a limiter and will/ should this fix the noise. and should the phasers be replaced also?
thanks