I replaced all 8 COPs about 18 months ago with the globals off of eBay. Now, at least one of them is acting up. I pulled all 8 out the other day hoping that I'd see something obvious--no such luck. Everything checked out fine.

What would you do?

1. Buy 8 new ones from Global again and don't worry about their "warranty".
2. Go to Ford dealership and have them figure out which one is bad and replace just that one.
3. Buy one COP from the auto parts store and replace one at a time until I find the offending COP.

 

from what i read on here, global doesnt care so much about warranties. i'd just stick all the coils back in and unplug them one at a time and see which one doesnt make a difference. then you can get another coil for 10 bucks from global or uneek. or you could get another full set and use the others as backups. its up to you. it beats paying for 1 motorcraft for the price of 8 from global. throwing parts at it will cost alot more than it should. is the cel on?

 

Well by acting up what do you mean? Did you replace the plugs when you replaced the cops? If not those could be the problem.

 

Got one brand new one I will sell you for 30 shipped. I know you can get them for 36 shipped I think from global, but hopefully you will take this one off my hands. Brand new never put on the truck. Just let me know if you go this route.

 

By acting up I mean that I'm getting an occasional misfire between 45 and 60 mph when the transmission is in O/D. Usually it's when I'm maintaining a steady speed up a hill on the highway. No CEL and no misfire at idle or under normal conditions.

I replaced all 8 plugs at the same time with the same plug that was in there from the factory - Bosch maybe? I can't recall but I know it was the exact same plug.

@ju015dd: I appreciate the offer but I don't know if it's worth going this route.

I guess my thinking is that my time is more valuable than troubleshooting this for a week or two while I change out one COP per night until I find the right one. Knowing my luck, it would be the 8th one! :-)

 

Very easy to find the one that is not working right. Start the truck, pop the hood and then start unplugging cop's one at a time. If you unplug it and the engine bogs down and sounds rough the plug it back in. Keep doing this till you unplug one and nothing changes. That will be your bad one.. This worked for me with finding my bad one last month.

 

If you have Bosch plugs in there, get rid of them and put Motorcrafts in.

 

I don't have a misfire at idle though. I'm not sure how this would tell me anything. Am I missing something? Now pulling the plug while driving 50 down the highway when I'm getting a misfire might... volunteers?

 

my local for dealer will stress test for $75. Did you use lots of dielectric grease? Could be some water got in there and fried one of the coils. Modulars are very picky about the plugs Motorcraft NGK or Denso work others are prone to failure. Might be a good idea if you just did it again..

 

I can see Jbrew volunteering himself on his truck with his daughter driving, saying... hang on Daddy, you'll find it. Just came to mind when you asked for volunteer's.
Anyways, back to your problem.
I put a set of Globals in 03/2008 and one out of the box was N/G.
It was extremely difficult trying to get that one replaced, but they finally came through. If it were my truck I would buy a set from Uneeksupply on Ebay. If I had to buy one from Ford, $90.00, one from NAPA, $58.00, all 8 from Uneek, $80.00 and I would have seven extra's.
In the last couple of weeks, I have experienced a low grade misfire now and then at low idle and on a rare occasion around 1400-1600 rpm's. I'm not to worried about it though because it happens when it has rained alot around here, and yes, I did use dielectric-compound when I installed the COP's.
90+ % of the time, the truck runs great. I have been wanting to order a set from Uneek and now I will since this has happened, just to have around.
I have no CEL and when I hook up my Equus Scantool, I get no pending codes and all my PCM Monitor's are GREEN, (meaning all have continually passed their diagnostic testing.