So the truck in my sig I've had a few years and changed the exhaust manifold to pacesetter headers and changed the spark plugs while I had them off. From my Haynes manual it states to gap the plugs to .044 which I did for the new ones the old ones on the other hand.....I'll let you take a look


As you can see the new is at .044 the old ones where either never gapped or not properly gapped they were at .072.



Here's all the rest. Truck ran good but when I would start it it would roll over 1 or 2 times more than I THINK it should. After the new manifolds and plugs all is right with the world.

 

I would say they were probably properly gapped when installed, but look like they got a lot of miles on them. The miles(use) causes the gap to widen. I see they are Autolite, so they wouldn't be the original plugs. For the previous owner, it was probably a matter of if it ain't broke don't fix it. How many miles on your truck?

 

I also see autolite... cheap **** makes me sad.

Motorcraft plugs arent expensive....just saying.

 

Autolite spark plugs aren't that bad. I will certainly take them over AC or Champion. Actually Motorcraft and Autolite used to be made by the same company, I don't know if they still are or not. Even though Motorcraft and Autolite were made by the same company, the Motorcraft did seem to last longer.

 

As of now the truck has 133,000 miles.

 

Well, kinda bad on you more than a previous owner if you've had it for several years and the plugs look like that. I've used Autolites almost exclusively for 35 years and never had a come back or washed out set. AC and Champion are not good in Fords IMO AC has major quality control issues and if you ever get a set of champions wet (flooded) half of them will never fire again. I have used some NGK in the last few years because it's a small town and that's all they might have on a given day. No problems with them

 

It is weird- Autolite or Motorcraft ALWAYS seem to work best for me in Fords- AC in Chevys(though I haven't owned one in two decades), and Champions ONLY work well in Chrysler/Plymouths! I do run Autolites in my WWII Dodge and my 1974 TR6, and both are fine...

I find it interesting that some brands of plugs apparently work better in some makes than others.

That all said, I agree- The mileage and age opened the gap on those plugs.

Scott

 

I do agree with that too but have used Autolites in them all with no issues. Plus Autolites numbering system is so much simpler and easy to remember.

 

I bought the truck in 2012 with 125,000. It ran like it should and putting on less the 10,000 miles since purchase didn't see the need for plugs. Has had the regular oil changes and lubrication plus the minor problems here and there.

 

I did the same thing, except I checked a couple plugs when I bought it. They were nearly new.

About a year later I went through and changed everything in preparation for a cross country move - they never changed the back 2 plugs. When I pulled them out they were worse than the ones shown. Previous owner had a receipt for the last tune up.

These are the reasons I do my own work.

 

You are right about the motorcraft ones lasting longer. I used autolite and they ran just fine, but were pretty worn after only 10,000 miles.

 

Haha, just ran into that on an 89 460 I bought last week, 5 champions and the 2 rears autolites

 

Motorcraft and Autolite spark plugs come out of the same Honeywell factory on the same assembly lines....just saying.

 

I know they are made by the same company, but my experience and some other people I know have tried auto lite. They run just fine but don't last as long.

 

They last just as long for me.