Spark plugs

[Greenman]

When did they become so awesome? I just changed mine at 115k, the book says every 100k. I could have easily run those things another 100k. They were worn, but nowhere near worn out.

 

[NutBucket]

They spent a few more bucks on materials just so they could claim 100k intervals. Nothing wrong with copper plugs 😉

 

[pcgeek11]

Probably iridium tipped plugs.

Very Hard metal and lasts a long time.

Iridium - Wikipedia

en.wikipedia.org

 

[ondma]

I think my Civic had platinum tipped plugs. Lasted well over 100k miles. Actually I could not tell that they were losing any performance. I just changed them because I didnt want the old plugs to get stuck into the cylinder head.

 

[mindless1]

Automakers were using platinum over 20 years ago, and those were also, often spec'd to 100K mi.

Yes you can clean and re-gap plugs and keep using them. It's often done in 3rd world countries. Here in the US where supplies are plentiful and incomes are good, people often opt to replace the wires at the same time because several year old wires with 100K mi on them can get brittle and work fine until you disturb them.

ondma makes a good point about pulling them every now and then so they don't get stuck.

 

[Greenman]

Automakers were using platinum over 20 years ago, and those were also, often spec'd to 100K mi.

Yes you can clean and re-gap plugs and keep using them. It's often done in 3rd world countries. Here in the US where supplies are plentiful and incomes are good, people often opt to replace the wires at the same time because several year old wires with 100K mi on them can get brittle and work fine until you disturb them.

ondma makes a good point about pulling them every now and then so they don't get stuck.

That's pretty much on point. After taking the plugs out, why not put in new? Plug wires aren't an issue as Ford doesn't use them.

 

[Jimzz]

The fine wire plugs usually don't wear, the tip will either break off or the plug will fail in some other method. Cooper and older platinum the tips will wear down slowly. So that is why they get changed even though they look good.

That and also getting them out can get worse with age. So easier to replace when they are still easy to get out than later.

 

[EXCellR8]

...I just changed them because I didnt want the old plugs to get stuck into the cylinder head.

You could also do any future owners a solid by throwing a very small amount of anti-seize onto the threads just below the nut. This is especially helpful if plugs are less easily accessible like in some boxer and traverse mount V engines.

 

[thecoolnessrune]

That's pretty much on point. After taking the plugs out, why not put in new? Plug wires aren't an issue as Ford doesn't use them.

Same for Subaru. For a while the service manual used to say Check Plugs every 60K miles. Now it just says replace them every 60K Miles. Because while you're taking the plugs out, you might as well.

 

[RLGL]

You could also do any future owners a solid by throwing a very small amount of anti-seize onto the threads just below the nut

See the following article, Pay attention to #1 (from NGK)

 

[EXCellR8]

Yes, that's why you only apply a very little bit to the threads furthest from the electrode. Certainly not a requirement, and aluminum heads are soft enough that you typically don't need it. Needless to say that if you put a ton of it on there and are then over-torquing plugs then you have no business replacing them in the first place.

Factory installing dry is typical, however after miles of changing heat levels, expansion and contraction, plugs can still get stuck.

 

[BonzaiDuck]

On the matter of the anti-seize compound. That's a good idea. But that's why I replace my plugs after -- say-- 60K miles. I want to be sure they can be properly removed, so at that point, why not just put in new plugs? I've used platinum plugs and iridium plugs now. The new plugs apparently don't need to be gapped. My Trooper has 188,000 miles on the engine, and never ran better than after the plug replacement last spring . . . Of course, I'm also using Premium gas, and I've been adding a half of a tiny bottle of Lucas fuel-injector cleaner to each tank. I can turn the key without touching the accelerator with the engine cold, and it just starts right up.

 

[Greenman]

On the matter of the anti-seize compound. That's a good idea. But that's why I replace my plugs after -- say-- 60K miles. I want to be sure they can be properly removed, so at that point, why not just put in new plugs? I've used platinum plugs and iridium plugs now. The new plugs apparently don't need to be gapped. My Trooper has 188,000 miles on the engine, and never ran better than after the plug replacement last spring . . . Of course, I'm also using Premium gas, and I've been adding a half of a tiny bottle of Lucas fuel-injector cleaner to each tank. I can turn the key without touching the accelerator with the engine cold, and it just starts right up.

The premium fuel is a waste of money unless you've had the engine tuned for it.

 

[pcgeek11]

On the matter of the anti-seize compound. That's a good idea. But that's why I replace my plugs after -- say-- 60K miles. I want to be sure they can be properly removed, so at that point, why not just put in new plugs? I've used platinum plugs and iridium plugs now. The new plugs apparently don't need to be gapped. My Trooper has 188,000 miles on the engine, and never ran better than after the plug replacement last spring . . . Of course, I'm also using Premium gas, and I've been adding a half of a tiny bottle of Lucas fuel-injector cleaner to each tank. I can turn the key without touching the accelerator with the engine cold, and it just starts right up.

You do realize that the accelerator pedal does nothing with the injectors or fuel delivery until the engine is started right?