I found bit and pieces of answers to my questions here by searching but not a complete picture, so I will start this thread and maybe others will find it useful...

I have a 2004 F150 Lariat Triton 5.4... It only has 53000 miles. I finally had cylider 1 misfire the other day.. Cleared the code, gonna sea foam it and see if it clears up... most likey it won't... My question is, since I only have 53000, should I maybe just change the COP and if that doesn't work, the single plug? I read somewhere it is better to change all plugs at 50000 or so, because they are easier to get out... (less miles, less carbon build up I guess)
Should I maybe go ahead and proactively do all? Also should I change ALL COPs at that time? Do COP "wear out" ? or are these we are seeing just quality fallout? I mean do some last 300,000 miles? or are they expected to go before?

 

If it was mine and being an 04 with the original style plugs, I would go by the TSB and replace all the plugs with the newer style 507 or 515. Supposedly a better design plug. The COP's should last at least 100,000 mi unless one gets wet and cracks. Just my .02

 

If you are gonna change the COP's and decide to upgrade to after market ones do them all at the same time. I had a set of GMS Coilpacks on my 06 Mustang and DID notice a difference in how the engine idled...it was an improvement by pricey!

 

Change all the plugs now with SP507's or SP515's. If it still misses, then start thinking cops. You can buy a full set of cops on Ebay for about $125.

 

i changed my plugs a couple weeks(worst job ever) my truck has 94,000 on it.i left the cops though

 

Use Chevron Techron instead.....your motor will thank you.....

To determine if it is a cop switch the bad one with a known good one and see if the misfire happens on the one you switched it with....

Check out eBay for cops....global or uneek are the two stores that have them for a reasonable price.

 

Thanks everyone for the advice... What is the difference between SP507 and SP515? I mistyped in my post, my truck is a 2005... does it still have the older plugs?

 

The 507 is single platinum, the 515 is double platinum. They are both revised, and ALL factory 2 piece plugs are the old style.

 

I have an 05 5.4L FX4 and had the plugs changed at 58K or somewhere around there....truck ran great up til ~77K and then started to develop a shudder at idle occasionally. I changed the COPS to some Global Automotive ones and the truck ran great for a week. Then #7 injector stuck open the other day and it was towed. Injector was replaced and the truck idles better than ever....now I just have a catalytic converter to replace after the injector failed.

After my COPS change the truck idled like it was brand new. I was shocked it could still get that quiet as I have the cam phaser noise.

 

Do you think changing the COPS and the fuel injector were related or coincidence? I have had 3 injectors replaced... I can't remember which numbers... the dealer that did them can't tell me either. I would feel a lot better if that #7 was one of them... that seems to be the common one.

Does anyone know if they fail like this after they are replaced? (I know anything can fail at anytime, but can I assume the 3 I have had done most likely wont re occur?)

I was really leaning toward the E3 one piece plug, but the dealer told me point blank that if I used anything other than Motorcraft, that the 11 yr 120k mile warranty for the injectors would be void.

 

I have a miss in the high RPM range that I've narrowed down to a COP. Code was thrown for cyl 2, swapped COP's with cyl 1 & 2, code re-appeared on cyl 1. Try it, it's an easy diagnosis.

 

The new injectors are from a different supplier.....which are less prone to failing.....

As far as spark plugs voiding the injector warranty....
Ask your dealer about the Magnuson/Moss Act and see if he understands that....
Ask him also if you use valvoline 5-20 instead of motorcraft 5-20 if that also will void your injector warranty.....

 

[QUOTE=88racing;4477600]The new injectors are from a different supplier.....which are less prone to failing.....

As far as spark plugs voiding the injector warranty....
Ask your dealer about the Magnuson/Moss Act and see if he understands that....
Ask him also if you use valvoline 5-20 instead of motorcraft 5-20 if that also will void your injector warranty.....[/QUOTE]



I understand and agree with you completely, I would think forcing someone to use a certain brand (Motorcraft) when there is a competitive equivelent could be considered a monopoly, and thus wrong if not actually illegal.

Hope he cant tell I am running Royal Purple... LOL

 

My fuel injector failure was just random and not related to my Plug or COP change. Truck was running AMAZING after I changed all my COPs out. Now I worry that the fuel injector failure fowled up the COP or Plug on the #7 cylinder. So I'm hoping I don't see premature failure of those parts because of the amount of fuel dumped into the cylinder.

Changing the COP's to Global Automotive was fairly inexpensive $102 for 8 COPS, Ford installed them at $167 out the door.

 

That should also be covered under the extended injector warranty. If not, there's the 8/80 emissions warranty.