Iv got a f-4350 with the gasoline 5.4 motor in it, and the number 8cylinder has lost compression and im pretty sure it's a burnt valve.
My question is I think Iv located a motor for a good price would it just be easier just to change out the motor and use the bad motor for parts?
Iv got a friend that has a shop with everything I would need like a engine puller.
I just really was wanting to know if it would be worth my time thanks

 

Easier is a relative term.

Here's some things you might consider:

How many miles on each engine?
What is the service history of the replacement engine?
Can you run and thoroughly test the replacement engine?
How much is the replacement engine vs. how much to have the one head rebuilt?
Are you sure it is a burnt valve? If so, what caused it?

Good luck either way you choose.

 

I bought the truck used so I'm not sure of the service history, it looks like it's been worked on before as all the seals look new and there's a helicoil in the number 8 cylinder the cheapest I found to have someone rebuild it is 700$ labor not counting seals and any parts that are bad or having the head rebuilt. Im not sure what caused the burnt valve ? And im not sure that's for sure what it is. It has lost all compression in the #8cyl it don't use oil or water and taking the valve cover off all the valves are moving right.
I found a replacement 5.4 same motor for 850 shipped

 

142,000miles on motor
Oh yeah and the replacement motor comes with a 6month warranty

 

Unless you are emotionally attached to your current motor, I would get that replacement.

 

Believe me im not lol I think that's what I'm going to do. Iv pulled motors out of Chevy trucks is there anything I should know that's odd about pulling this motor ? Or is it pretty much straight forward

 

I haven't pulled one, but I don't think there is anything unusual.

Maybe you could take pics and do a write-up.

 

are you sure the helicoil isnt leaking? The previous owner must have ot of one any maintence on the truck for the plug to blow. And helicoil in a aluminum head Ford is ONLY a temp fix it will blow again. Id check and double check to be 100% sure the helicoil isnt the problem before i go any further

 

Iv tried to see if I could hear air blowing past the plug but im not really sure how to test it ? I did pour some lite wait oil in there to check for bubbles but didn't really see anything ?

 

best bet is to start the truck and get a long screwdriver and stick it on top of the coil, if you hear ticking or air hissing threw the screwdriver you got a problem

 

unless this previous owner NEVER changed the oil i cant see a mod motor blowing one valve out, especially when you say you can see them move freely when you removed the valve cover? i still say its the helicoil, maybe the mechanic cracked the head at the spark plug hole when he tried to install the helicoil in the first place? How did the truck run when you first bought it?

 

It had a miss when I bought it but I jumped on the deal too fast, my guess was that a coil pack was bad... I only paid 3000$ for it. Lol
But now I know why they were selling it.
It looks to me like someone has had the motor apart before because most of the seals look brand new, but so does the timing chain and guides.
So I really don't know what happened