Hello,
I recently purchased used '97 Expedition with a 4.6L Triton engine (129k mi). The spark plug for the #3 cylinder blew out of the head while driving on the highway this week. I did some research on the internet and found that the Triton engines are famous for this due to a lack of threads in the head for the #3 cylinder spark plug.........I had no idea.
There are specialized inserts available to repair this however, I don't think that my cylinder head is a candidate as a piece of the head along with the threads are missing. Also, my understanding is that Ford does not recommend using the inserts. Instead, they recommend replacing the head.
I'm curious if the replacement heads sold by Ford are designed differently from the original to address the issue with the plug thread deficiency?
The problem apparently been resolved in the '05 and newer engines. What did Ford do to fix it? Will an '05 head work on a '97 engine?
Any help/information offered is greatly appreciated.

Regards

 

Yes you can use an 05 head. The problem was there were only 3 threads holding the plug in. Starting in 05 the heads came with 5 or 6 threads. You can get rebuilt heads on eBay for a lot less than what Ford will charge you.

 

Alloro,

For the record, so the newer heads will work even though they were designed as a 3v motor instead of the original 2v? I'm taking this as there is no compatibility issues? Thanks.

Also, sorry to hear about the plug ejection. It was by accident that I actually found out. I did a Google search for "ford 5.4l problems" or something like that and it was one of the top hits. Although it bothered me, I still bought my '97 and did a plug change within the first month of owning it. When I removed the plugs, for me, number 3 was pretty "loose" feeling compared to the others. Good luck and make sure the dealership or whoever uses anti-seize and torques the plugs properly.