Derf00

08 models were built from Aug/2007 to July/august of 2008. The updated head with new 1-piece short reach plug was released in Late 07 (Nov 07).

Mine was built in Oct/2007, it's an '08 model with the older 2-piece plug design.

Derf00

Sorry I do disagree on that one, Somewhere on this forum there is a thread about it...and it was figured out unofficially that the actual production date was around nov/07. Most likely Feb/Mar 08 would've been when cars with the updated head were starting to be sold on the dealer lot?

I could be wrong on that but I'll see if I can find the thread or official source...

Found a source....

http://www.enginebuildermag.com/2013...-dohc-engines/

Bottom of the first page...

"On engines built prior to Nov. 30, 2007, Ford used a two-piece spark plug that has a long steel tubular ground electrode around the center electrode. This is necessary because the plug extends deep into the cylinder head so it can be positioned near the center of the combustion chamber."


and here under "Spark plug issues" However I believe the actual release date is incorrect. It was thought that Oct 2007 was the release date but the thread here on the forum contradicted that and it was settled on as Nov 2007. https://en.wikipedia.org/wiki/Ford_Modular_engine

BrianK

Apparently some 07's got the new design too. When I took my 07 to the dealer and asked them to check based on my VIN, they said I had the newer design, but I told them I had black COPS. That is when the service advisor laughed and said it could be up to $1000 if they all broke.
The tell tale is - black COPS = 2 piece design; brown COPS = new design (not 2 piece).

Derf00

Yep, this is a definite.

trackers

just started my supercharged 4.6 after winter sleep. it's skipping and gives a 3 and 4 cyl miss fire. possible plugs? 24,000 miles, any idea?

justinmiles73

I have a 08 gt that was built in November of 2007 and it has brown coil boots. I put NGK iridiums plugs in it 2 years ago no problems so far.

SCCAGT

I stand corrected. I just remember reading back about that time that it was Feb 08. no problem

Plugs are always a possibility. Especially when under boost conditions. My factory ones had to be changed at about 10000mi, due to misfiring under boost pressure. If you change them, might want to get plugs 1 step hotter than OEM.

Goldenpony

Hotter or colder?

SCCAGT

I jumped the gun. Higher heat range number makes it a "colder" plug.
My lefty loosey, righty tighty went bonkers.