My .02 on spark plugs. I own a 2006 5.4L.
How I remove mine without breaking them and install with no issues afterwards.
First: You will need a professional grade carb cleaner spray and brake cleaner. Possibly a few cans of both. Carb cleaner for the plugs and brake cleaner to clean the engine brush (which I will spell out why below).
Next: Blow out the spark plug well with compressed air after removing the ignition coil.
- Spray a professional grade carb cleaner down in the spark plug well so that the liquid is about 1/4 to 1/2 inch deep.
- When removing the spark plug, using a "back and forth" unscrew/screw method and patience is your best friend. When you go to break the spark plug loose, loosen a very little and then retighten. Keep doing this and go by "feel". As in when the plug becomes becomes loose in that little amount you went back and forth on, loosen a little bit further and keep repeating this back and forth motion until the plug is out. It will be time consuming, but this is what I do and remove plugs without them breaking. If it continues to be tight, let it sit in the 'loose' position that you were able to get it to and let the carb cleaner work and then resume your back and forth motion. You may need to 'top off' with carb cleaner periodically since it evaporates.
- After the spark plug is removed, take your carb cleaner spray and an engine brush such as this and clean the spark plug threads (in the engine) thoroughly. Take your time when cleaning the spark plug threads. When you pull the brush out to inspect the amount of crud on it, spray the brush clean with brake cleaner until the brush comes out clean. Then stick the brush back down into the spark plug thread and spray more carb cleaner in there and continue to clean. When the brush comes out pretty much spotless or close to it, the threads should be clean.
- Cover the spark plug well with something thin and breathable such as a shop rag and allow time for it to dry after cleaning the threads.
- Apply nickel anti-seize to spark plug as indicated in the Ford Tech Make You Loco video above.
- When installing the new plugs, use a torque wrench and torque to the correct spec.
While this may seem odd, I have found that the 5.4 does not like dirty spark plug threads and doesn't quite run right and also the plugs tend to back out.
Also, for what it's worth, I use Autolite HT15 spark plugs in my truck and it runs just fine and it has been at least 6 years. I got the "back and forth" instructions off Autolite's website back when I bought my truck, but it is no longer posted on their site. No, I do not work for Autolite or any auto company.
Lastly, I must reiterate - Having clean threads in the cylinder head on the engine when reinstalling is EVERYTHING and while it may seem odd, I promise it's worth the time.
