should I Change my COPS and plugs? I have 45,700 miles on my '05 ?? or is it too soon?

 

I'd say a little to soon on the plugs and I wouldn't touch the coils, ever. Unless your having problems with them.

 

I would not touch the cop's but I did the plugs in my 04 at 40K had a ford dealer do them as per the TSB and they broke 7 of 8 and they did not look that bad to me but the replacement plugs are one heat range hotter and they used nickel anti seize on ground shield so guess it is your call, I erred on the side of caution since I had the x tended warranty it only cost me $300 which is the cost to change plugs on these engines, it is a very poor design which ford has since changed.

 

Had a COP go bad (@ 42,000 miles BTW) on me a couple of weeks ago which got me looking at this forum. I've got the 4.6L which means I don't have to worry so much about breaking plugs, right? I believe the 4.6L engines are 2V and don't have the problems with plug breakage but some things in the forum are confusing. Sorry if this question has asked a million times.

 

NO plug problems on the two valves since late in 03. Yea, you never know when a coil can go south on yuh. My first didn't go bad until 185,000 miles, replacing them all at that point could of made a big difference, I really can't say they did because I changed injectors at the same time. - Between the two, the truck went from a heavy slug to light on it's feet, -so to speak.

 

If you are not having drivablity issues then why do it? Yes, you have to worry about plugs breaking. If you are really wanting to change them out then make sure you are really prepared and know how to do it or have the cash to do it. Otherwise let them be.

 

As tim98 said, if you're not having any issues, don't worry about it. These engines can go 100,000 before they need plugs, and the COPs should only be replaced when needed. You'll know when a COP goes bad as you'll get a check engine light showing which cylinder is misfiring.

Aftermarket COPs are also a waste of money. I have never seen a definitive gain on them, for anyone else who is thinking of this...

 

If you have a 3 valve, check the TSB, I believe you pull them @ 60,000 miles. Next time, post your engine size so you don't get the wrong info.

 

I do have the 5.4 with 3 valves.....

 

Ok yea, you'll get more posts about just that, but I think the guys were pulling them at about 60,000, -just the plugs.

 

To be honest, I'm not sure how you'd check them without replacing them. Mine came with the engine, which had well over 100,000 miles on it before I put it in the Mustang. I haven't had any issues that I know of.

With plug wires, you could always check the resistance across each one and compare with the rest. I have no idea how to check a COP.

That would be good info for this post, if anyone knows how...

 

Hmmm, doesn't seem like there's a way to test without specific equipment:
https://www.f150online.com/forums/v8...coil-plug.html

 

I have the original plugs in my engine at 165,000. Dealer and local garages are VERY reluctant to fool with it until it can't go any further. So far, so good. They were excellent at 100, 125, 150k so dealer said leave well enough alone. i got a new truck so I will sell this one off ,4x4 Super Crew, and put money to new one, same thing in a '10. new one is pretty nice..Lariat..I like the console but it does cut down a LOT of space.

Also bought a V6 Escape...a real rocket!!

 

Note to self: do NOT buy malking's used truck.