I've got a noise between 900-1100rpm that is most pronounced from the drivers side wheel well. Truck sounds completely normal at idle and above 1100rpm, and it has been driving fine. Its an '08 5.4L with 55k miles. From doing some research, it seems like its the VCT's engaging and it happens to quite a few trucks.

Below is a video I took (hot engine); I'm sitting in the drivers seat holding the gas pedal to keep the engine at about 1000rpm, and I am holding the phone down near the bottom side of the opened driver door.


Any thoughts as to this? Is it doing any damage running the truck the way it sits? What would you suggest doing? Replacing the VCT solenoids? I would really like to do whatever necessary to avoid any cam phaser issues!

 

mine has sounded like that for the last 90,000, just keep 5/20 in it with a motorcraft filter, and live with it.