About a week ago a noticeable tick started coming from the injector pump or somewhere in its vicinity. I just got the truck back from the shop and they said that the pump checks out and the sound could be a noisy injector or a lifter. They told me to run some fuel additives which I already do (Valvoline). I've got 65,000 miles on it and run it pretty easy. The juice was just upgraded to hot about a week ago just after I started noticing the tick. So I haven't even ran the truck with the hot juice passed level 3 cause I'm worried about the ticking noise and the probability of it coming from the pump. Any thoughts?