Ah, so your approaching your 100K mile mark or you have recently developed a misfire in your 3 valve 5.4 liter Triton. I am sure you have heard of the warnings about changing spark plugs on the Ford 5.4L. There are always risks with this type of surgery. I will try to explain and review every method I have heard to ease the removal of the spark plugs, but ultimately it is up to you to choose a repair path. You should combine several of these methods to determine the best results.
This is a step by step guide describing how you could change the spark plugs on the Ford Triton 5.4L 3valve engine. Specifically, it is referring to 2004+ Ford F150 VCT engine. This does not include previous generations built on or before 2003. Even though those have spark plug issues too, its a very different problem. As a forewarning, this is not a job for a novice. A spark plug removed incorrectly could result in expensive engine damage. This amount of damage usually requires the replacement of the cylinder head.
There is definitely a handful of tools that you will need. Any pneumatic or power tools can and should be used to save you valuable time and energy. I have compiled a short list of useful and required tools, although there may be some that you need that are not on the list. Some specialty tools are listed during the step requiring their use. You can check out my Master Recommended Tool List for other general suggestions.
Long Reach Needle Nose Pliers
5/16 Spark Plug Socket & Extension and/or
OTC Extended 9/16 Plug Socket
Motorcraft SP-515 Spark Plug OR newer design Motorcraft SP-546
Lisle Broken Spark Plug Remover for Ford Triton
**ESSENTIAL TOOL** This is your life saver. This is the tool that removes the broken sleeve from the cylinder head.
Before you attempt to remove the spark plugs, it is important to understand why you must have that tool. These spark plugs are special. They include a special tip that normal plugs do not have that extends them down into the cylinder head. This tip fits very tightly inside of the head. After several thousand miles (approx 100K) repeated heating/cooling cycles combined with carbon build up and lack of use of anti-seize during assembly, the special tip becomes seized into the head. Once you turn the spark plug, most likely the tip will break off from the rest of the plug and remain down inside of the head while the spark plug will just unscrew like normal. If the plug appears to come out easily as you turn it, most likely it has already broke off. If it makes screeching noises and is hard to turn, but still turns, you know you are successfully removing the plug completely intact.
The problem lies in the fact that sometimes people can easily remove all 8 spark plugs and not break one, while others can try to remove them but break all 8. The lisle tool works by pushing the main electrode down through the spark plug about an inch, and taking basically an specially sized easy out to thread into the tip to grip and remove it. It has a high success rate. However, pieces of the electrode or porcelain may chip off and fall down into the cylinder unexpectedly and cause damage when you attempt to start it.
The plug can break off several ways. The threaded cap could break away from the stuck sleeve leaving the whole porcelain plug intact, snap the porcelain leaving behind the center electrode sticking up, or snap the porcelain flush inside taking the electrode out with the threaded sleeve.