Hi, New to this site. I installed a P-1SC on a f-150 5.4 2003 It took three race shops and about 2700 bills to get it to run correct. I have yet been able to tell if it runs correct. It sure makes a lot of rattles along with the wissle. The rattle appears to be comming from the tensioner arm but may actually be comimg from the supercharger. Since I have never heard another one on any vehicle I do not know. I have heard a Vortech and a Whipple and a Eaton, NO Rattles just plain good strong wissle. I have checked the oil level and all connections, even double checked with the race shop that finally got it to work. Only problem is they had never heard one either. Any body know if this is familiar with Prochargers?:confused: