I own a 2007 Mustang gt with an auto tranny. My car has a faint diesel like clatter at idle and clatters when driving in a parking lot when I’m at 1200 rpm. I don’t hear a startup rattle tho. I am planning on getting hotrod cams in the future. I want to know if I should lock my phasers out or just replace them because I daily drive my mustang and I heard phaser lockouts are more reliable but cause torque loss.

 

Depending on which cams you get, you may not have a choice. Some require lockouts.

 

I’m trying to get ford performance hot rod cams

 

I wouldn't lock them then. Cam profiles are designed to either work with, or without the phasers locked. If you gp against the recommendations of the cam mfg, you can end up with poor performance or even engine damage.