I'm getting ready to do the dreaded spark plug change on my 2006 5.4L engine.I bought the new plugs at my ford dealer,but after looking at them I think they are 3 piece plugs just like the originals.I thought they updated these to a one piece so they wouldn't have the breakage issues?A friend of mine claims that any ford part number that ends in F is the non updated part and ford is just trying to sell the old inventory first.Does anyone know if these are the updated plugs,or should I use a different brand?

 

This intrigued me so calling the local Ford dealer I learn the longer number is indeed Ford's p/n for that plug---its Ford's number and would indeed be exactly what was installed new on your motor.

See if your dealer doesn't offer SP-515, MotorCraft instead--that should be the latest updated part. Even though it seems to be a similar part number it is unique and therefore quite different.

Take 'em back, get the right ones from MotorCraft and don't use another brand---its not advisable.

HTH

 

Just bought a new set from O'Reilly the box is marked SP515 but has PZH14F on the plug wonder why and if there is any difference old or new stock???2005 F250 SD 67000 MI.

 

SP515 is the current spark plug. They are still 2 piece but are beefier in the crimp area and have a better electrode design to help with high RPM misfires. The heads and plugs were redesigned in late 2008 to 1-piece and look similar to a 4 wheeler plug. You have to change the heads to get the 1-piece plug. Once you get the old ones out you shouldn't have to worry about the plugs breaking. Just put some anti-seize on the ground shield and you will be set. Be careful not to get any on the electrodes.