With all this talk and me with 52k it was about time to replace the plugs. I also followed the other thread and decided to do a little work in the subject. I bought Autolite double plat. plugs today, P/N APP103 for $3.99 at O'Reilly. Here are some links to some photos. I looked closely into the head and it looks like the treads DO NOT go all the way up to where the plug seals against the head. In the photos you should be able to see where the plug seals, then a dark area, then a shiney area at the bottom where the threads are. In the pic of the plugs you can see my gapping tool (I gapped them to .054). This tool makes sure the eletrod is not angled. I can only leave the pics up for a day or so, so download them if you want. We can email them around if someone misses them.

Rob



Coil
hole1
hole2
hole3
plugs

 

Becareful, you may have gotten the wrong plugs! Too much thread......

 

rob n houston,

Thanks for the pictures, it makes more sense now. My truck has 75,000 on it and I'm debating replacing the plugs soon. Any tips or heads up ? Did you notice any performance gain?

Thanks....

GAV10 Mark

 

Jade, nope not the wrong plugs unless Autolite and others are making the wrong plug and giving the wrong P/N. I checked several websites and they all referenced the same plug. the parts guy doubled check it when I picked it up. The only different plug between a 99 v10 and a 2001 v10 was the Motorcraft plug. And I would have expected this. If you reread the threads you can see it makes no difference how deep the threads are. Bosch, Autolight, Champion and others have figured this out. It does make you scratch your head and wonder why Ford made the head this way.

As far as tips, well I only changed out 4 last night. I did 1,2,6,7. The easy ones of course. I was going to do only one but 10 minutes later I had the others done. 1,2 and 7 were all very tight, a good snap to get them loose. 6 wasn't quite as tight. NOT to say it was loose. I will say if you don't have access to a air nozzle I might not attempt this at home. You really need to do a lot of blowing to clean around the hole before, during and after the change. I did one at a time. With the dirt and blowing it seemed logical. The coils come out pretty easy, a little side to side twist as Iron... recommended and they come right off. I guess the plug connector is a little loose, no jerking like the old days. To remove the connector on the coil you press the release on the bottom, comes right off. Then I believe it was a 8mm or 5/16 hex to remove the coil. My small 1/4 rachet was handy. Pretty basic after that, I have a 5/8 plug socket with the rubber plug holder, remove the plug, stick a new one in there and tighten. I tighten them pretty snug. When tightening they hit the bottom and that was it. The threads didn't feel mushy at all. On the drivers side you'll need to remove the air snorkel. I didn't look at anything else because I didn't go any farther. Maybe I'll do a couple more tonight so the process won't seem so bad. And no I have no fear that changing out a few plugs at a time is going to hurt my engine.

I will say the autolight's double plat. look exactly like the OEM's (except for the threads). A platinum tip on both tip and eletrode.

Rob