I post this in hopes that it will help other beginners like me.

My wife's 97 Mountaineer was running rough at idle and was loosing power. A code scan revealed a misfire on cylinder 3, so I decided to change the plugs and wires. I was already overdue as the vehicle has 130,000 miles. I started on the drivers side figuring that I would do the hardest ones first. It was slow going, but I managed to get those four done and moved to the passenger side. Number 4 came out fine, but number 3 wouldn't budge. Following some advice I read here, I sprayed it with penetrating oil and moved on to 1 and 2. It was now 1:30AM and the plug still woudn't move at all. I got desperate and stupid and created a cheater bar. I slipped a piece of pipe over the end of my socket wrench handle and leaned on it. I felt some movement, but then there was no resistance at all. I reached in and spun the socket off by hand. The top hex part of the plug had sheared off the lower threaded piece. Luckily, the insulator did not break and all of the ceramic came out with the plug socket.

The next two days were spent tracking down the right size extractor, spraying the area around the top of the plug remnant with penetrating oil, and scraping at the rust with a screw driver and o-ring tool that looks like a dental pick. I was finally able to back the plug out yesterday. The head was not damaged and when I got the new plug in the engine ran great, smooth with more power.

Things I learned from this experience:

1. Allow plenty of time. I started this project late and ended up working into the wee hours.
2. Be patient. I got in a hurry and that ended up costing me two days time. Plus countless stress worrying about what it would cost to have someone pull, then drill and tap the head.
3. Regular maintenance is your friend. If I had done the plugs when it was recommended, I may have not ended up in this situation.

 

One thing I noticed too... and it has been said... I can really tell the difference with MC plugs and wires... seems like Ford engines really like their brand name plugs and wires - glad to hear you didn't ruin the threads, or that it did finally come out...

I know many like autolite plugs too... but I will never do the job again with anything but OEM Ford parts for this type of job. I'm sure you can use aftermarket stuff in other places, but this was something I didn't want to have to do again for another 60K :-)

Thanks for your post

 

I did go with with MC plugs, but I bought Autozone wires. I wish I had planned ahead and gotten MC wires as well. The Autozone set, Duralast I think, were just about the right length on most cylinders, with one or two being too long, which left some unsightly slack to deal with. Two other things; on the drivers side, two wires have heat shielding where they run very close to the exhaust header. On the factory part, the shielding is a flexible metal tube, Duralast has a lined silver fabric. The factory cables were stamped all the way down with cylinder numbers, no numbers on the Duralast cable. I suppose they meet technical specifications, but don't match the Ford part exactly.

 

I think the most important aspect of changing plugs is to make sure you put anti-seize on the new ones when you install them. This will avoid the problem you had. Some people unknowingly put wd40 on plug threads when they install them. While this may make it easier to do the install, over time with the engine heat, the plug will 'bake' itself to the head. Just my 2 cents...

 

I think the wires are the more important thing actually, as you found out - but what happens is that the heat from the engine breaks down the insulation, and then, when the wires get damp, like from overnight dew, etc, they fail... That has been what I have learned in my travels and in real life experience... never used Duralast wires, but I LOVE their Batteries! the gold tops are great!

 

I can't get MC plugs here, I have to use NGK Iridium, they seem to work ok.
They are the OEM plugs for the Monaro, our version of the GTO.

The plug leads used in the local Fords are great, I wouldn't swap them for an aftermarket part.

I use a tiny bit of antiseize with molybdenum in it on the threads.