I have no problems with my truck, has 95,000 KM. Bought it a few weeks ago a 2007 FX4. No trouble codes, so whats the point in changing out spark plugs if all is good and all cylinders firing. I have no idea if plugs have ever been changed. So should I change them now when all is good or wait for one plug to go, why not wait. Like the old saying why fix something thats not broken. Or is there good reasoning in changing plugs every 50,000 KM.

 

Are your COP boots black or brown? They're probably black, which means you may have the breakage issues if you do change them.

 

I definitely wouldn't wait. The longer you put it off, the better the chances of breaking them!

 

I like to change out the plugs asap when I buy a used vehicle...Just for peace of mind.

 

Black boots, change!!!

 

Oh boy... I'm about to replace the plugs and COPs on my 2006 5.4L for the first time... I did them in my 2000 5.4L, but have yet to read up on here to see how the 3v engine differs from the one in my 2000. What's up with the black boot COPs breaking? Do I need to be worried about it if I'm replacing them anyways?? (sorry for thread hi-jacking!)

 

It's a crap shoot really. I changed them on my 07 FX4 before 10K just because of all the issues but that's just me. Some guys won't ever change them unless the truck dies. I just couldn't stand to wait. Got to be the biggest design flaw Ford could have ever come up with. At least our accelerators don't stick like those Toyota's!!!

 

It's not the cops that break, it's the spark plugs. The brown cops were used on the redesigned heads introduced sometime in 07 or 08. You have some reading to do in this forum and the V-8 Engines forum. If you just go in there with a wrench like you did on the old one, you will most likely break the plugs and leave part of them stuck in the heads.

 

^ agreed. Do some research.

 

X2^. I recently changed my '04's w/ only 50k miles, followed the latest TSB to a 'T' and still ended up with 3 broken plugs. I strongly recommend you research this topic and do not attempt it unless you have the Lisle 65600 tool or comparable method ready. I have a pic in my gallery if you want to get an idea of why we all dread it. Not the hardest job to do but your PATIENCE will be tested.