Your post needs a little qualification.
After about 2002, the 4.6 heads are not known to blow plugs out due to insufficient threads.
If the plugs are not tightened enough, any head can blow them out.
The 5.4 heads used on that motor are the ones known to blow plugs up to about 2002 due to the small number of threads. This was fixed by a revision in the head castings.
As to the 4.6, my truck is a 2002 4.6 and has had 5 sets of plugs in 321,000 miles without any issue.
Be sure you look at the big picture before making the statements.
Good luck.

 

The head castings on the 4.6 and 5.4 were revised midway through the 2003 model year. However, there ARE a few 4.6's in 2004 trucks that have the old heads.

Torquing the plugs to 28 ft/lb pretty much eliminates the blowout issue.

 

I'm so sorry. I didn't mean any harm. I was just trying to keep others from suffering the consequences I had to deal with. I bought my 2000 F150 new and it now has 642,000+ miles on it. After I rented the TimeSert tool and put in the third plug that blew out I decided I was done with that problem. I now have TimeSerts in all eight cylinders. I was only trying to give back to the group because I have received a lot of help from you guys over the years of working on this wonderful piece of equipment. Once again, I'm sorry for the mis-information.

 

I changed out all 8 spark plugs on my 5.4l 2 valve recently and I used this tool (see below). It really helped to ease the job for me.

 

Once again the problems have reared their ugly heads. Same code P0113 and P0308. Ran a bottle of Iso-Heet and Techron at 5/8 tank of fuel. I had changed all plugs(Motorcraft) and coils(Denso) back in August, and while I don't drive the truck often. it was running fine until today. That's a total of about 300 miles total. I do find it odd that these are the identical codes as before the new parts were installed. I have a new fuel filter that I plan on installing, but I don't think that's going to solve the other issues.

Not sure of what to do next?

 

what Brand Coils did you install recently?

If they were Not one of these 3:

Motorcraft, Denso, or Delphi

as glc suggested to you in an earlier post... you may have a bad coil already.
Some of the parts we can buy at auto parts stores are Not very well made, depending on the Brand.

I purchased all my Coils from Rockauto.com online. I bought the Denso brand which are supposed to be identical to the motorcraft brand from what I have read on coils here.

I also used a liberal amount of dielectric grease into each coil before installing down onto the spark plugs, it is supposed to help with ease of installation and also helps keep water away from the spark plug and inner coil.

***are you losing any Coolant? the truck I own came with maintenance records from the time it was purchased new and back at about 180,000 miles there was a intake leak back at the left rear of the intake manifold/driver side and had a miss on #8 cylinder.
The shop ended up replacing the intake manifold And the #8 coil to get it back running correctly again.

 

Denso coils
Lathered up with dielectric grease
No coolant loss

I'll be back at it tomorrow, but the one thing that there seems to be no explanation of is how to make sure the coil spring centers itself on the sparkplug? I spun the COP back and forth trying to accommodate this, so either I didn't accomplish this, or it's not really necessary. I don't know.

 

Make sure there is no dielectric grease on the spring or the plug terminal.

 

That might be the problem then. I pulled the boot of the new coils and lubed both ends pretty heavily. Live and learn I guess? No grease was put on the elec. connector side.

 

Plug terminal? the top end of the spark plug?

Why no grease on the coil spring? It is my understanding the Dielectric grease helps and in no way hurts transferring electricity... No?

 

You do not want any grease on the contact areas. It's only for the boots.

 

Your understanding is correct. There is no need to abstain from getting grease on the electrical contact areas. Wherever there is going to be metal-to-metal contact, the grease will be displaced.

 

In my opinion the term name 'Dielectric' is misconstrued to be an insulator.
There are many compound grease like applications that are used on electrical connection, for a verity of reasons.
The grease used for coil boot application serves two purposes.
A. Since you cannot see to set the coil boot on the plug tip, the grease helps the boot find the plug terminal and prevents the boot from hanging to the side.
B. Some amount of moisture proofing at the spring to plug terminal and porcelain.
It serves no purpose to coat the spring but does not affect operation.
If you notice the spring has a carbon rod section inside. This carbon rod serves to short circuit the Inductance the spring could add in series with coil to plug tip that has the capability to generate other electrical issues if it were not in place.
Last, the grease as you apply it, goes into a semi harden state once heated from the engine heat.
It's presence also helps in breaking a bond that may form between the boot and the plug porcelain over time.