I had the same problem, at first I thought it was because I hit a fairly large puddle I didn't see driving to work one morning. Then it happened again, took it in and had it rapaired. The dealer said that their was some sort of seal below the windshield by the air intake that was cracked or split and was letting rain water in and on top of my coils which was shorting them out. I think to replace that seal was around $40 with labor and all. I hope this helps.

 

I'm in the process of replacing all 8 COP's, 6 done. For grins I measured the primary and secondary impedance on the 6 old ones (0.55 ohms is spec for primary and 5.5kohms is secondary spec).

All 6 measured 0.5ohms primary and 5.2-5.3 kohms secondary.

I measured a new one and got 0.6ohm primary and 6.0kohm secondary.

Anyone every measure their old/new COP's?

I guess all 8 have just plain worn out. It's running better, but not prefect when cold still. I'll know more when the last 2 are done (these 2 are the ones deep in the hole on the passenger side).

Best,
jeff

 

I'm a newbie and need some info. Have a 2002 F150 with 5.4 liter engine. Have had two of these coils assemblies replaced at the dealer. Killing me with BS and cost. Specifically, where are these things located on the engine? I don't have a lift, so I'll be crawling on the ground looking for them if required.

Thanks!

Hank

 

They are located on top of the engine over the cylinders. They each have a single screw holding them in. Along each bank of cylinders, the COP's and the injectors alternate. If they are the originals then they have a motorcraft sticker on them.

If you read up on the issues related to misfires, when one COP goes, they are all getting ready to go. I guess they just sort of wear out electrically.

A shop manual might be useful for what to do to replace them.

Best,
jeff

 

So you guys think that you should replace the other 7 when 1 goes out? I replaced one COP almost a year ago and another one in April. Do you really think I would see any improvement by replacing the other six? I've had a bit of a rough idle and I've cleaned/replaced everything under the sun. It's not throwing a CEL, but it does idle rougher than I think it should. Is it possible that the 6 old COP's are to blame?

 

It depends, if they have been wet before or if your trucks has over 100k I would seriously consider it. I replaced 2 COP's way back when, paid $60 a piece for them and the truck ran okay for awhile until another went bad. I ran across that deal on ebay - bought that set and it made a night and day difference.
Ran across another deal on ebay - Ford factory COP's , New from an 02 4.6 crate motor - The guy was selling the top half of the motor. I ended up buying the COPs $160 the injectors(type 3's - awesome spray pattern) at $60 along with the wiring harness because my harness wouldn't except the new injectors they had a different type plug on them so that was $60 as.

They were all new never used. My truck had about 168k on it then and I'll swear the truck has never run this well, even when it was new it didn't run like this. , it's responsive , the biggest change is that it feels light and not heavy slow, it's been fun to drive since then. lol

I have 200 thousand on it now and it hasn't changed , very happy with it, however I now need a trans for it now $##$!@$, oh well..

 

Hey JBrew. Just wanted let you know, I finished replacing all 8 Coil Packs and it is running great.Thanks for the advance.... The final two coils took forever to remove!!

 

No prob, replacing all eight at the same time has it's advantages with these motors - It keeps it's integrity in place, and everything just jives..

 

Just to add to the benefits of replacing all 8... I didn't have time to replace all 8 at one time, I did 2 first (first 2 on driver's side). No change to my rough idle/chugging when cold, still bad and still no CEL.

Then replaced 4 more - last 2 on the driver's side and the first 2 on the passenger's side. NOW I got a set code - P0304 I think it was - misfire on cyl #4.

Changed the last 2. Voila it's fixed, smooth idle just like before. (note I had already changed all 8 plugs).

From my measurements on the 8 old COP's all were below spec. on primary and secondary impedance. I guess they just all get weak at about the same rate.

Best,
jeff

 

Did you use a digital reader? That made a difference when testing priy & secy resistance on the coils. It really didn't matter in my case - The way I see it , they all were bad lol

 

i found some at autozone for $38, definitely beats the $80 from the dealer. also took a look at my injectors, the #7 was pretty clogged, don't know why but i cleaned out the spray holes and it helped a lot.

 

Well my plugs were changed at 68k and should have had the COPS changed then but didnt. I justed changed them at 78k and my MPG went back up to 15.5 mixed driving so I am happy. The Ebay coils are what I used. Checked and you can get a set of 8 now for 85 bucks plus shipping so like a bill total. I would jump on it if your COPS are getting old or just to have a set to ward off any problems later.

 

I just had the same problem (water in the plug tubes) and got the 8 COP's from global, did the plugs at the same time. I have done it about 7 or 8 times before between my truck and a buddies, It only took me 2 hours and that's spending 45 mins fishing out a rock from beside a plug, and then ANOTHER ONE!!!! you can do it yourself, just take some time and be prepaired to have to have a lot of paitence! My truck feels so much better now, even from before the miss, better throttle response and better gas milage, went out to the mountains on the highway and got 19 MPG, that hasn't happened for a very long time, I think the last time was when it only had 285's and no lift.

 

I am about to order a set of (8) COPS from Global, and have been reading about this dialectric grease you guys say to use when installing them. Where exactly would I apply it? Inside the boot where it goes onto the plug, or where the little wire connects up on top? Thanks alot!

 

I pull the boot off the coil and do the entire inside of the boot. The spring should connected to the coil when you do this - if not , you have to fix it so it does.

Anyway , grease the inside of the boot (all of it), slide it back over the spring , don't worry about getting that grease on the springs, that's okay.

Then apply grease to the top seam of boot and a dab on the bottom - then install. Twist it a little back an forth when it comes in contact with the plug.



Then grease the void between the top of the boot and spark plug chamber to seal it off . Silicone wire sealer or dielectric grease on the connector as well.