Ticking / knocking noise on 2004 Ford F150 5.4L?

I would add some Lucas oil stabelizer, or STP to the engine. if it is the lifters rattleing it should make them stop or make them quieter. I would have to agree with the mechanic who listened to the engine making the noise. Experienced people know the differences in the sounds ociated with a running engine. Rattles, pings, knocks, and thuds are all different sounds to the trained ear.