Ive been hoping around this site and havent really got the awnser Im looking for so I hope I can get help on a new thread.

Awhile back the truck wouldnt start. I found out the problem was the GEM. I had it towed to the dealership cause I couldnt figure out what gem was the right one to order off the net. The dealer talked my wife into scanning the gem before replacing it and low and behold, a wire was dissconected.

Soon after that the truck started running poorly, or well not up to snuff any way, and so I researched everything here and changed the plugs. (Wow!!! what a nightmare!!!) Since then Ive had 3 cops go bad. Twice its been old #4, the worst one of the bunch.

Well, I dont know if its gone bad actully cause I havent checked them, can you plug them in with a spark plug in place and lay it on the engine to watch the spark?

The reason Im asking is some say that its just water getting in there, and I read that I should use dielectric grease and an other guy said the grease wouldnt really help, and Im wondering that if theres enough water to short out #4 all the way up under the windsheild shouldnt #3 be shorting out too?

My wife says the truck runs like its missing and that it started out only missbehaving going up big hills. Now it runs like its missing all the time.

I HATE!!!!!!! changing that #4 cop. Can it be something else that I missed?

I didnt use grease, do you use it were the cop mates to the head to seal it off or around the part that goes onto the plug?

If it is water in the plug hole, will the cop work after the hole is dried out?

Is there a way for a down home guy to check a cop out of his truck?

Thanks in advance

 

Just Primary and Secondary resistance but that's really a waste of time. Because that's not where they fail. The best way to test is in real time. Monitoring each individual coil during the drive cycle. If you searched, then you should know how. I've explained that and described how many times.

Search the "Engines" forum only. Or the lightning forums - the procedure has been posted in both.

 

Well I finally got the dealership to go with me on a test drive with their computer hooked up. During a climb on an incline, it detected a misfire on cylinders 1,3, and 7. They pulled it in the shop and tested all of the COPs , no defects detected. So their telling me that Ford wont authorize any parts unless the dealership can show some data showing a defective part or parts. Any ideas on how we can convince Ford to authorize the repares would be greatly welcomed. Thanks, Doug
05 f150 5.4L 3V