I know there are a lot of threads out there on spark plug changes. I have read A LOT of them and have done many searches over the past year. Today I tackled the plug change (took all day but got them all changed). We had 7 break. The only reason the 8th didnt break is because the dealership changed it when I bought it. Anyway, it now idles very rough and misfires during normal driving. I drove around the side streets for about 10 minutes because I read the computer needs to reset and still very rough. To the point where I dont want to drive it. At first we had a DTC code (p0357). Turns out we forgot to plug the COP wiring back in on plug 7. Reset the computer again, and still very rough. Any suggestions? I also installed all new COPs. Could it be one of them is bad? Will I get a DTC if I have a bad COP? Again, sorry for making another post about spark plugs but like I said I have read and searched a lot and dont have the time to keep reading a thousand threads. Thanks for any suggestions.

 

What brand plugs and cops did you use? Did you use dielectric grease in the cop boots? Did you get all the broken porcelain out of the cylinders after you extracted the plugs?

 

There is a possibility you didn't get the COPS down on all the plugs. They are a little difficult connection sometimes.

 

The plugs are motorcraft sp515. The cop and boots are the eBay ones that are recommended by many on here. Not sure which ones, ill have to look. I might try putting the factory COPs back in. We did use dielectric grease. We blew out the cylinders best we could with a compressor and small hose to get right in.

 

plug in all the injectors?

did you loose any big chunks of plug down inside the cylinder?

 

Is that the plug in that goes to the top of the COPs? We did get all those after we realized we missed one. Now they are all plugged in. The tip of the broken plugs did break off (the part that goes around the electrode to ark off of) we did blow out each cylinder as much as possible.

 

The cylinders need to be vacuumed, not blown out. You may need to pull the new plugs and look for damage.

The Ebay cops have been known to be bad out of the box, it's somewhat of a crapshoot.

You may have gotten grease on the actual cop/plug contact area - that can be troublesome. You need to be careful and grease only the inside of the boots.

 

Damn, I must have missed that part. I just blew them out. Will I get a DTC if a COP is bad or how will I know?

Now I'm confused where the grease is supposed to go. We put it at the end of the boot and the tip of the plug? So it sounds like we did exactly opposite of what we should have?

 

The terminal end is where the grease goes. Thats the end the cop connects to.

 

Yea thats what I thought. I am confused by the previous post.

 

You do not want grease on the wire contact area. Only on the inside of the boot to assist in it going on the plug. It can also be used on the outside of the boot to help insulate. If you get it on the wire connector, it can interfere with firing.

 

Alright. I am going to have to pull the COP/boots and wipe them. So the spring inside the boot should have have any grease on it? how do I get grease inside the boot but not on the wire contact? Since its already in there would I be better off just putting the old COPs back on?

 

Best way to grease just the inside of the boot is with a Q-tip. Pull the cops and the plugs, inspect the tips of the plugs for damage, then take some lacquer thinner and clean the grease off the cop springs and plug contact ends.

 

Still no luck guys. I have been working with it all day. I have changed back to the original COP and put the new boots on them and it is still rough. I wiped the grease off the boots and spring and got down to the spark plugs without taking them out and wiped off what I could. Would that little bit of dielectric grease cause the engine to be running this rough? I'm still getting the sputtering during accelerations, rough idle in park, low power. I havnt got any CEL codes other then when I missed plugging in a coil wire. Which I have cleared and reset the computer by unplugging the battery. Would my next step be to take out the plugs and see if they are bad? I also checked all the injector wire plugs and they seemed fine.

 

Yes, PULL the plugs. If there was something in the cylinder when you fired it up, it can beat up the plug tip. You also could have damaged a valve. If any of the plugs are damaged, I'd recommend you go rent a borescope before you put new plugs back in.

You DID use high temp nickel antiseize on the ground sleeves of the new plugs but NOT on the electrode strap and NOT on the threads, right?