Just got done swapping out my plugs at 100,735 miles. (2005 5.4)

I had pulled them and reinstalled at around 50,000 miles, and they came out the same way both times, firm, squeaking, but without problem. New plugs are in, along with fuel filter, trans filter, trans flush, transfer case flush, front and rear diffs, and radiator.




Overall, very pleased with how they look, uniform carboning and wear. And yeah, I know ther's only 7 plugs shown...one of them got tossed before I thought of posting a pic.

 

Wow, this is funny. Another member on here tried to dispell the FACT that spark plugs do NOT last up to the 100,000 mile claim....
Yeah right!


Good to see you’re the norm when it comes to plugs and didn’t panic and replace them at some rediculous interval like others on this forum.

Thanks for the close up pics too! They do look a bit rich, but it's the point that todays plugs do indeed last up to and beyond the 100,000 mile spec.

 

Well that makes us two the only ones I know of that went to or over 100k with the stock plugs. Except I never pulled mine before they hit 100.

 

my parents 5.4 has 65,000 on it and we havent changed them yet. i dont see why they cant last 100,000

 

When you say "...us two the only ones I know of..." I hope you realize that there are literally millions of vehicles out there with 100,000 mile plugs in them. The handfull of F150's on this forum hardley warrant any credability to the belief that 100,000 mile plugs don't indeed last to 100,000 miles....

Obviously some folks may have a dud batch of plugs, but that's a drop in the ocean when all things are considered.

 

You pulled them at 50000miles only to put them back in? Id figure if you go through the trouble to pull them you might as well spend a few bucks and put some new ones in.

I dont think anyone on here disputes the fact that the plugs will last 100k miles, the issue here is that the plugs will not perform at 100% at 100k miles. In other words you could effectively run tires until the wires show and the tire blows, but obviously the tire will not perform optimally which is why they are replaced earlier. Can they run that long? Sure. Should they be run that long. Well it depends on how much you expect out of your truck and the level you maintain it. I expect the most out of my truck and likewise I maintain it with high standards.

A 100k mile spark plug, as obviously seen by the posted pics cannot and will not perform like a clean, non carboned up, and corroded old spark plug. Its simply electron flow, the high voltage eventually eats away at the metal and over time will not arc(misfires). This may cause lack in power, rough running, etc. But if all you are concerned with is your truck getting you from point A to point B, then dont worry about it. For those of us that have high standards of expectations and think of a vehicle as a little more than as a means from point A to point B, then well replace the plugs when they need to be replaced to perform optimally, not when Ford tells me to.

 

My old 2000 still had the orignal plugs in it when I traded it in for my 05 and it had 96k on it I don't plan on chaning the plugs until I hit 100k on this one.

 

Seriously, your analogy is ridiculous. No one in their right mind would drive a vehicle with tires wore down to the belts. If you notice NO degradation in performance or gas mileage, then why would you bother replacing the plugs? Because they have the typical build up on them?

Let me make one thing very clear, in no way am I advocating waiting until the plug reaches 100,000 miles before you consider having a look simply because it’s supposed to last that long. I am simply disputing the narrow minded comment that a plug can not last until a 100,000 miles. Again, let me reiterate, if you do not have any degradation in performance nor fuel mileage, then why bother? I probably will not leave mine in ANYWHERE near 100K, I’m too ****, but to make a blanket statement that they simply can not last that long is uneducated. As for some of the people on here that have replaced them at 10,000 or 20,000 miles, well, unless the plug failed, they just don’t really understand mechanics at all.

As to MY standards, a picture is worth a thousand words. I suggest you have a peak at my gallery if you want to see where MY standards rank. Substantially higher than the average joe.

 

Those plugs look fairly good. I personally think no plug should stay in for 100,000 miles. I think they should be part of the routine maintainence regiment.

 

These are pretty sophisticated/Platinum plugs, we're not living in the days of 30 years ago when plugs fouled out at 30K, mostly because the carburation was so bad.

I seriously doubt there is ANY difference between the performance of his truck Today with the new plugs than Last week with the Old.

I run my Synthetic blend oil to 7k before I change the oil. I just changed the fuel filter for the first time in 75k miles and my truck still runs as good as the day I bought it, and as good as everyone elses who changes every do-dad out there every 500 miles.. By the looks of those plugs I won't be in Any hurry to change my plugs at 100k miles...

 

For what it's worth:

I average 1500 miles per week. Yes, per 5 day period (I don't drive the truck on the weekends-it's my office). Since my original brake pads are still at 75% , it is obvious that this truck does not see "normal" use-it is, literally, 98% highway mileage.

Since I keep records of every mile driven and every gallon of gas purchased, I can tell you exactly where I was, the weather condition, the passenger and cargo load in the vehicle, and the gas mileage for literally every mile driven. I doubt any of the "experts" out there have records anywhere nearly as complete as mine.

When I pulled the plugs at 50km there was no obvious reason to replace them. They were as clean as could be expected for something 7 months old-the difference being that mine had two, three, or more years of use on them at 50,000 miles. There has been no performance or mileage degradation from 10,000 miles to 100,000; the only reason I changed them now is because even though they ran fine, the 100k is as good a benchmark as you will find. If I drove "normal" use, I would be much more concerned and probably would have changed them long ago. The fact is this: they didn't need it before this, they didn't really need it now, I just did it.

And if I may, I would caution you against telling me your are any higher than mine, because in my profession, I literally place my life in the ability of my vehicle to perform. rms8 is correct-while someone else's may not last 100k, mine obviously did.

 

The big clue here is 98% highway miles.
That type of driving is much easier on a vehicle then some one who does stop and go, short trips or towing. But the plugs still should last 100k.
People that say they won't last that long are probably the same ones who change their oil 3 times before it hits 3000 miles.
Spark plugs, oil, filters and the engine controls are light years from where most people are stuck at.

 

I want to do the pluggs in my truck, or at least take a look at one of them. I have 53k miles and the trucks been sluggish... I hear they are hard to take them out???

 

My friends 1988 Jeep Cherokee has the original spark plugs and 300,000 miles.

 

just replaced mine at 84500. came out hard, but no problems. just cracked them loose, sprayed rust pennetrant, waited 10 minuits, removed them. just as the tsb says. it did sound horrible.If you did not know about the tsb. they would probably break off. Mine looked pretty worn. the gap was much bigger than new. the little tit on the electrode was completely gone and the corners of the ground bar were rounded where the spark actually grounds. I would agree that they will last 100k, probably longer. I think the concern is the spark plugs breaking off and the smoooth running and efficiency of the engine. I wasnt going to put the old ones back in. I payed 77 dollars for a set at Napa.