So, as I continue to battle a random misfire in my 5.4, it got me thinking about replacing the engine. My truck is near mint condition, regardless of the odometer showing 213,000 miles, so I would like to hang onto it. I don't use the truck for work like I used to, but it's my daily driver. Logic says, just fix the misfire. Believe me, I'm trying. But having this issue appear randomly every few weeks or months, changing coils, wrenching under the hood has gotten old. Not to mention the heads have had inserts put in them and that issue is always in the back of my mind, too. And she's been using more and more oil lately. Get a new truck. I like having a truck, as it is handy, but I don't need a $40,000 + truck or payment and I don't want to start over with someone else's problem. I called Ford this morning and to my surprise, I can still order a brand new engine from my local Ford dealer for $5,332.00. To me, that seems like a pretty good deal. Just swap over my brand new intake, another new set of coils and accessories, and I should be good to go until I keel over. But I have a question that the parts guy couldn't answer so I'm hoping someone here can; Did Ford make any improvements to the heads on these regarding the plugs blowing out like mine did? It would really suck to have that happen on a new engine. I guess now that we know of the issue, just tighten the plugs a bit more before putting the new engine in, maybe? I don't know. Share your thoughts with me and let me know if anyone has gone the brand new engine route

 

Is it really a brand new engine?

Ford used to make re-man short and long blocks?

I'm sure if you did some more research, it is likely Ford improved the engine problems on later model engines.

You would have to find that out and then order one from that newly improved era, providing it would be a direct fit.

 

I want a direct replacement. Ford went to the 3 valve in 2004, so not many years to develop improvements. And the 3 valve has it's own share of problems.

 

Unless the misfire is caused by a base engine mechanical problem, you'll probably be chasing the same misfire again, but on a new engine.

 

There is that possibility, too. That's what makes this random coil pack issue so frustrating.

 

We just put in a new Ford crate motor yesterday; it took a few days. It was 6.8L V10 in a F5500 2009. It is quite a job and the motor was supposed to be new from ford and looked like it. We paid $8.5K in the Peoples socialist Republick of California. It started on the first turn of the key and is running smoothly. You can't go wrong with factory parts (once you get the correct one)).
Mike

 

@GN1220 , I believe this will answer your initial question about the spark plug blowout issue. It seems that in November of 2002, Ford updated the heads from having only 4 spark plug threads to having 8 spark plug threads for the 5.4 in order to address the spark plug blowout issue. It also seems like there may have been a revised spark plug design/model used in these newer cylinder heads. You would likely need to verify the casting dates on the cylinder heads of your "new" Ford engine or remove a spark plug and count the number of threads in the cylinder head to verify that you got the updated heads.

https://www.justanswer.com/ford/5znx...nder-head.html

 

I wish I knew that in 2016 when I had the heads off getting inserts put in them. Would've save a lot of frustration and worry.

 

Have you done a compression test on the existing engine? Had the valve covers off to inspect the valvetrain?

 

Yes, a few years ago. 😄 I just can't figure out this random miss that comes and goes. I understand, like was pointed out above, if it's an electrical issue that it will do the same with a new engine. It's just frustrating.

 

Last picture is at the least a burnt valve ?

 

It's definitely a little short of metal . . .

 

Yep. I bought it off ebay from Tacoma and the dealer said it ran great. Shipped it to Kansas City and it had a miss. Discovered a blown plug and a ****ty repair. Ended up pulling the heads and having inserts installed. That was in 2016.