ReaperHWK

Just curious, because I'm having slight misfires and read through a ton of posts and a good deal of recommendations(after changing plugs first) is to replace all the COP's with motorcraft.


Then I go and read that after the COP's are changed most people still have misfiring issues. I did my plugs a year ago and that cleaned up the misfires (they were terrible), now I'm getting them again. I'm going to do the boots first before I mess with COP's, I didn't replace the boots when I did the plugs. I also read it's good to actually use a wire brush and clean out the holes in the head to remove carbon, I'll give that a shot after I change the boots.


Has anyone actually found that the factory coils go bad? I would think they are just electrical coils and would be hard pressed to fail. Seems like most people throw on new coils as a step in the process but it doesn't fix the problem 90% of the time.

BadFish523

I had a miss on cylinder 2. Replaced the coil with a cheap brand from Orileys and the miss is gone. I plan on changing all of them with cheap coils (but not Accels) when the weather warms up.

connorfx4

I read an article years back that said COPs don't go bad. It's the spring inside the boot that goes bad. I've always only changed the boots and springs with success.

GigaFish

I have fixed misfires by replacing coil packs on my truck. I started out doing one at a time but ended up doing the last 4 at once. I also heard that it is the spring in the boot that goes bad, but I have had pretty good luck finding OEM Motorcraft ones for a good price on Amazon so have just been doing the entire pack.

Summers22

iTrader: (2)

I have never had a OEM coil go bad. This on 3 trucks with close to 200K. My trick? Take the boots and springs off, then take paper type fingernail files and cut them in half short ways, then halves again length wise. Use 1 section per coil and sand down the copper contact in the nipple of the coil. Replace the boots and springs with either Motorcraft or BWD (I have had perfect results using BWD). Put a little dielectric grease on the part of the boot that slides onto the nipple, then a little dielectric grease on the end of the boot that goes on the plug. Think of these boots as old school plug boots, they get cracks, get old, brittle, have carbon blow by on them. They arc and cause misfires if they get these symptoms. For about $35 it's worth a shot. It have worked perfect for me all 4 times I have done this.

techrep

iTrader: (1)

What DTC's are You getting?

ReaperHWK

I don't get any codes, I can just feel it. Even when my truck has misfiring so badly(previous to my plug change) I never got codes unless I was going uphill on part throttle and the truck started bucking violently and the Check engine light was FLASHING but it stopped after it stopped misfiring.


There are no stored as far as I can tell, the light is not on.




I'm going to try what Summer's suggested, that sounds like a plan. I REALLY don't want to spend $300 on new coils, when I think they HAVE to be a low failure item because all they are is electrical windings (I wonder if many people who replaced COP's the actual problem was the spring/boot and the COP itself is fine?). I also read a good post on here that stated that it is a good idea to run a wire brush in the spark plug holes because the carbon buildup can affect plug firing as well, going to give that a shot too.


Right now it misfires slightly, I can live with it until spring when it gets warmer and I can do the work more comfortably. I changed plugs in 15 degree weather before, it was a PITA, and I broke every plug. I'm not doing that again.

BadFish523

Also in regards to this, I kept the old coil. The boot looks good, the spring does look a little corroded on the tip. I believe someone had done some previous work to the coils (fingers crossed they did the plugs too) as they used WAY too much dielectric grease. They basically just filled the whole end, spring and all with grease. I believe this may have been the cause of my problem. It was a really cold day and I think maybe some water or something mixed in with the grease. I watched a video that said a good coil will read 1.8 ohms and the one I replaced read 1.7 ohms. In conclusion I wouldn't doubt at all what Connor and Summers are saying. I kept the coil and plan to clean it up and keep it as a spare, but yes changing the coil did fix my miss.

BadFish523

You Tube

This is the video I watched that he says a good coil will read 1.8 ohms. He also shows how he cleans his coils up. The only thing I disagree with in this video is how much dielectric grease he uses.

elricfate

I wouldn't worry about how much grease he's sticking in there. There's metal to metal contact once you shove it back on, the grease just keeps other stuff from having points of ingress between the metal bits. It won't harm it to be stuffed full like that.