Ok So the truck has had a rough idle the past couple of weeks. It has been in the 10-30F temp range here the last few days. Thought I might be having injector problems so I ran a bottle of cleaner through; the idle smoothed out for a couple of days then it came back. So, out of curiosity, I pulled the sparkplugs to have a look at them. They are autolite APP 5224. They have about 25,000 on them now. The stock gaping is .40, but all of mine were in the .65-.75 range. Yes, I gaped them to .40 when I installed them. What would cause the gaping to change?

 

If I am correct, and I believe I am, over time the tips of the plugs errod due to the firing of them, therefore creating a wider gap. 25,000 is a lot of miles on a set of plugs

 

That's a hell of a lot of wear/erosion for 25000 miles. Last set I ran 25000 the gap was only .002 wider than set at when new.

 

I went over 50,000 miles in my 5.2L 1995 Dakota once on one set, and only two of the eight plugs were more than .45, and even then only about .5. OEM style plugs.

That is quite a bit of gap change for 25,000 miles.

 

eh, my truck doenst get tortured very hard, so I think that 25000 on one set of plugs is still minimum.
Here are some pics of the plugs, excuse the quality since I can't seem to find my good camera.



I know, I thought it to be weird too, thats why im asking .

 

When those plugs were put in did you do it or some one else? I never heard of a gap increasing that much.

 

I did it myself, and it wasn't the first time doing it. This is bizarre. Ill put them back in tomorrow regaped, and see what happens. I am wondering if its the platinum that's giving me issues. I know plats aren't necessary for our trucks but that's all Wal-Mart had

 

you sure you used the same gaping tool ? That's crazy , unless your burning the Shiot out of the electrodes somehow ....

 

The platinums shouldn't burn up as quick as the copper. That's really weird. Maybe you just got a bad batch of plugs or something.

 

wow i must have bad luck with plugs or soemthing. i changed mine every 7,000-12,000. Them seem to just burn up