I've had my 2010 Fx4 with 81,000 miles for 2 weeks and I've been hearing this rattle noise. It happens when accelerating very lightly from a stop. I also hear a fairly loud tick especially when the engine is hot from running for a while. Here is a video. It's a very short video but if you listen carefully you will hear the rattle. Can anyone give me ideas of what it is and how to fix it???

 

Cam phasers. Mine has that same sound. I also had rattling at cold startup. So tore into it and found tensioner seals blown out and broke guides. Figured that was all it was so changed them out. Still have the sound. I recommend changing all timing related things while in there.

 

Damn, you still have the sound??? So what needs to be replaced to get rid of the sound? I know the 04 to 08's were known for cam phaser issues but from what I've read, it was said that the issue was resolved for the most part from 09 and up. Must not be the case :-/

 

Yea at light throttle i have the ticking sound and the only thing i didnt change was the phasers. (Wish i would have now lol) but if i was to go back into it i would change everything. Chains, guides, tensioners and arms, phasers, vct solenoids. I thought the problem had been resolved by 09 too but i guess not.

 

I had this exact same sound for a year or two and it drove me crazy trying to figure out what it was. I have a 2009 Lariat that had the exact same sound. I noticed it most often when pulling forward in drive thrus because I could hear the sound reflecting off of buildings. In my case it was the passenger side exhaust manifold. It started with the sound you have and then after a year or two it progressed to adding a ticking on startup for a minute or so. Mine did not crack like many others have but it did warp badly and caused an exhaust leak that was most noticeable when the engine was cold and I would start it up. When I disassembled it it was noticeable on the gasket that it was leaking. I would start by investigating with a cold motor to see if it is an exhaust manifold. I ordered a new manifold (which came with the gasket and the two studs that connect the manifold to the mid pipe) and a set of studs from Rock Auto and changed it out and it fixed the problem. Good luck, hopefully this will help you diagnose it and fix it. It drove me crazy enough that when I saw this post I actually got a login so I could respond.

 

How much did that fix cost you??? I'm worried it's the cam phasers. I hear it's a common problem with the 5.4's :-(

 

I ordered the exhaust manifold from RockAuto and it cost about $60. I ordered the stud set online as well, I think from amazon and it was around $10. The exhaust manifold came with new gaskets and the studs for the flange to the remainder of the exhaust. My total cost was about $75 or $80 (including shipping) because I did the repair myself. There are some pretty good youtube videos on removing the exhaust manifold, it is a little tricky when you first look at it because there are 8 bolts and some can only be accessed from certain spots. Unbolting the manifold wasn't too bad but getting the remainder of the exhaust out of the way to remove it and position the new one was a pain.

 

Hmm. I wish I was more mechanically inclined. It seams like a difficult task to diagnose the manifold as being the problem?

 

Have this same exact sound as well. Mine was diagnosed at a local mechanic as being a manifold leak on the passenger side. It's not bad yet. I only hear it when I go through the drive thru at mcdonalds or something like that. He quoted me: "Around $450-500" to have it replaced. From what I was told people are usually getting charged around $500-$600. So it doesn't seem to bad for the price. However I'm not sitting fantastic financially so I'm gonna have to wait it out until it get's a little worse =z

EDIT: My uncle owns a Rail road company. And they have 3-4 F-150/F-250's with the 5.4's in them. A couple of them have the cam phaser issue. And none of them sound like it does in the video. A cam phaser (From what I've heard) doesn't sound so spaced out in between each tick? If that makes sense? It sounds like a more rapid/fast pace consistent tick. Not saying your truck doesn't have a cam phaser issue.. I'm just telling you from what I've experienced. It doesn't sound like it is. I have what appears to be the same exact sound/Problem and mine was diagnosed as a Manifold leak.

 

Well that's reassuring. I would much rather it be the manifold. So my truck sounds almost like a diesel (that's the best way I can describe it but I do think the video I posted depicts the sound pretty well). And I do mostly hear it when pulling through a drive thru. It also has a fairly loud tick... Especially when at operating temperature. Could that also be a sign pointing to the manifold?