Whether anyone reads this or not i felt it was necessary to at least post my experiences. I replaced my Motorcraft COP's with Accel for the obvious reason of cost. I did all new plugs and all new COP's at 100k miles. After about 10k miles i had a misfire, pulled the plugs and one was rusted into the engine and one had broken off the end of the electrode. Put two more Motorcraft plugs in and in about 6k miles i had another electrode break off inside the cylinder while driving down the road. Replaced this plug and about 10k miles later i had two more plugs begin misfiring. One the electrode was completely melted away and the other was covered in rust. Each time was a different cylinder. Sometimes 4, sometimes 8, and once or twice it was 1 and 5. I swapped over to Motorcraft COP's and put all new plugs in again and now here we are 5-10k miles later and no problems. The only thing anyone can figure is that the Accel COP's are designed to be a "performance" COP and the Motorcraft plugs just cannot handle the heat being produced by these COP's. Anyways just a little review from someone who has gotten very familiar with changing the spark plugs in a 3v 5.4 F150.

 

So where does the rust com from?

 

Did you use a dab of dielectric grease on the plug tips?


And I'm also interested in where the rust is coming from.

 

Was it rusty threads on the plugs or literally rusted sleeves that protrude into the cylinder? Did you take any pics?

If it was rusty thread then I assume no anti seize was used, if it was rusty cylinder side that seems like there is water in the fuel or something!

 

Or it is rusty because the boots of the Accel COP's are crappy, letting moisture get down in the 6" deep cylinder head. Although, I assume the "rust" is actual carbon which on the barrel of the plugs is a brownish color, looking like rust.

 

The base of the spark plug rusted to the point a mechanic had to sit there on the top of the motor with a pick and turn the plug a 1/4 turn at a time because there was no longer a hex shape to the plug base. It had rusted to the point that when a spark plug socket was put over the plug and turned it just free turned and rounded the entire base off. I took pictures at the time. I will have to see if i can dig them up. It was cylinder 4 and 8 that rusted the worse so the only thing i could come up with was it was residual water coming down off the cowl and onto the top of the motor somehow and as Summers22 said the Accel boot isn't as snug of a fit as the Motorcraft and allowed the water to drain into the spark plug holes. As far as anti seize goes we never had a single plug break off in the 16-18 plugs that have gone in/out of the truck. The only breakages have been the electrodes and hoops causing misfires.

 

 

Yep, has to be the Accel boot letting excessive moisture in, especially if it is the 4 and 8 plug hole. 4 being passenger rear and 8 being driver rear.

 

After 3 years with Accel COP's i understand why they are $150 for a set while the Motorcrafts are $35-65 a piece. I went ahead and swapped back to 8 oem's and called it quits.

 

Out of curiosity, could you not put an oem style boot on the Accel coil?