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!

 

I would bet its one of your ehaust manifolds leaking. What happens is one of the studs breaks and causes a gap between the manifold and the block and lets air pass by causing the rattling noise. It is most noticeable when the engine is under load or on cold starts and then quiets down after 30-40 seconds once the manifolds gets warm and helps seal that gap again.

 

It almost sounds like the cam phaser knocking noise I had on my 07 5.4 3v but not as bad yours is more of a tick. Supposedly it will get worse over time and become more of a knocking and clanking sound. I had my mechanic install the Livernois Motor sports cam phaser lockouts and the nasty sound is gone! One thing that is for sure with the vct thing tho is that it's more of a warmed up idling problem. When I would give the engine gas it wouldn't make the sounds. Let me know what happens tho!

 

Ps: the mechanic can get out the vct gear and install the lockouts without having to take apart the whole front end, contrary to popular belief. Just as long as the don't lose timing of it.

 

My 08' with 30,000 made the exact same noise at around the same rpm.
I could cause the truck to stall out if I didn't give it enough gas when in reverse. Both VCT solioids were replaced and now it runs fine.

 

I've had this sound, I call it a fluttering sound, since I bought my '06 4 years ago with 34k.
It now has 110K and the fluttering hasn't gotten worse or changed at all.
I've read a while back that it is considered normal by Ford and unless it gets worse (louder, stalling) you shouldn't have anything to worry about.

Aside from a slight stumbling at full throttle at 70K miles, fixed with plug change, and low grade misfire at 100k miles, fixed with new cops...motor has been flawless, and as strong as when I got it.

My opinion is don't fix what isn't broken, even though it is a lil annoying!

 

Did it ever get worse?