i would start with the coils plugs can be a hassle in these trucks here is the ford service bulletin
This article supersedes TSB 08-1-9 to update Vehicle Applications, Service Procedure and Part List.
The engine build date can be read on the left hand cam cover information sticker.
To remove spark plugs without damage, it is necessary to adhere exactly to this procedure before removal is attempted.
Spark Plug Removal Procedure
Separated/Broken Spark Plug Removal
If the spark plug separates after following the Spark Plug Removal Procedure, it will fail in one of three modes. Refer to the appropriate removal procedure as required.
Flowchart of procedure. (Figure 5)
Mode 1 Procedure:
Use Rotunda special service tool(NNN) NNN-NNNNto remove an empty ground electrode shield from the cylinder head. (Figure 6)
Mode 2 Procedure:
Mode 3 Procedure:
Use Rotunda special service tool kit(NNN) NNN-NNNNto remove porcelain broken inside the ground electrode shield. (FIGURE 10)
Porcelain Removal - Preparation
Porcelain Removal - Bonding Process
Porcelain Removal - Extraction
Porcelain Removal - Pin Slipped Out
In the unlikely event that the pin does not remove the broken porcelain, this process can be repeated.
Key elements to success are:
Replacement kit components and additional kit consumables (Loctite(R) 638TM Retaining Compound and pins) can be obtained by calling 1-800-ROTUNDA, Option 5.