I'm working on a 2005 F150 5.4 3 valve, 225,000mi. I can see the cam sprocket thru the oil fill hole in the passenger side valve cover, without the chain on it- I can see the chain sitting behind it. I asked the owner what exactly did it do? Make a hell-of-a-noise, then stop running? They said: 'No all it done is the oil pressure light came on then it started missing. Then it kept dieing on me that’s all it did. The engine light didn’t come on until after it died on me and quit.'
I know the 5.4 is an interference engine- my question, I guess, is should I be prepared for the worst? Be ready for a complete teardown?

 

I’d plan on a remanned engine. I doubt you got the whole story.

For the chain to jump like that, the chain guides have had to be in a million pieces clogging up the oil pump for a long time.

 

I drained the oil 🛢 in that truck into a bucket 🪣 and poured into a jug- that's what was left in the bottom of the bucket 🪣 --I cleaned out the bucket 🪣 before I drained it

 

Probably best to think about a used, or reman. From what you have seen with the sprocket, and the metal. It won't be simple repair and go. Once the metal starts showing up in the pan.......game over. I don't care what was said by the driver/witness.
Good luck

 

Curious on what you found with regards to the motor if you tore it down.

 

I haven't taken it apart, but I took the valve cover off and found this..... the cam sprocket/ bolt is broke off the camshaft

You can see the the broken bolt 🔩 lying under the cam sprocket

 

Well hell id still be curious if it broke and didn't cause damage. It would depend on luck though. But question is why would the bolt break? ....

 

Those bolts are hollow, and from what I've heard they are easy to over-torque

 

I'm not planning on taking that one apart, but.... 🔧
The owner found a used one, same year, wrecked but it runs - but it has 247,000 miles.
I pulled the motor but I thought: 247,000 vs 225,000 - I should at least take off the valve covers and inspect the timing chain/components 🤔 It's a good thing I did because I found/fished-out this little bit of timing chain guide....?!? I told the owner 🤑 now I'm waiting for them to get a timing chain kit