5.4 3valve spark plug replacment how-to
 

I recently replaced the spark plugs in my 2008 F-150 with the 5.4 v3-valve V8. As most of you have posted there is a design flaw in the 3-piece spark plugs that causes them to stick and break off during removal. After a lot of research and speaking with a buddy who is a Ford technician we came up with a plan of attack. First we ran a full bottle of Ford combustion chamber cleaner through the engine. The bottle was supplied by my technician friend but it can also be purchased at a dealer. After the combustion chamber cleaner we allowed the engine to run up to operating temp. This is a very important step. Most of the instructions I found online say to remove the plugs from a cold engine but I got my info again from a Ford tech. Us the correct socket, extension, ratchet (no air impact wrench) and all 8 should come out in one piece. The main thing to remember when removing is to listen for a "ticking" sound. As long as there is a ticking sound while you are turning you are in good shape. That means the plugs are turning and the carbon is breaking loose and not holding the plug. If the ticking stops the plug has broken and you have to go through the practice of extracting the end of the plug. If you have to do this the Lisle (LIS65600) Broken Spark Plug Remover for Ford Triton 3 Valve Engines is the tool the tech recommended. They cost about $100 so you want to try and find someone with the tool and borrow it. I hope this helps out some guys and you are able to do this with very little headache.

There are so many posts on how to do this... btw, the tool only costs like $50

I own the tool and never had to use it.

Been replacing spark plugs on these trucks since 2006 and never broken one. I always de-carbon the engine with seafoam or something similar, get the engine up to normal operating temp, use the correct spark plug socket and hit them with a 1/2 cordless impact. They NEVER break, using this method

You must own a very early model 08..