Spark Plugs! What's normal wear?

[CharBaby]

At 50K miles
At 100K miles

What should todays spark plugs look like for normal wear and color?

White?
Gray?
Redish?

Any pics would help too

Thanks,

CB

 

[SHOZ]

I changed the plugs on my son's '09 Chevy Malibu 4 cyl last spring. At 100k they looked as good as the new plugs I put in. I couldn't believe it.

On my '08 Accent the plugs are dark at the tip and graduate to tan the closer the ground strap is to the body.

 

[CharBaby]

On my wifes '01 Lesus RX-300 w/93K miles, the plugs look sort'a like this in the pic but, with a bit more white-ish residu(but, not ashey) on the center electrode. Mine look more like calcium deposits on only one side of the center electrode. This is the closest pic I can fine:

http://i465.photobucket.com/albums/rr14/Corysez/IMG_2460.jpg

 

[chrisri]

Well how long they will last depends upon car and spark type. New cars require iridium/;platinum plugs for longevity/ease of owning a vehicle. Brown or light gray would be normal plug color, but i had cars with all sort of colors; as long there is no excessive deposits it' all good.

 

[chrisri]

Originally Posted By: Char Baby
On my wifes '01 Lesus RX-300 w/93K miles, the plugs look sort'a like this in the pic but, with a bit more white-ish residu(but, not ashey) on the center electrode. Mine look more like calcium deposits on only one side of the center electrode. This is the closest pic I can fine:

http://i465.photobucket.com/albums/rr14/Corysez/IMG_2460.jpg


If it looks like this it's good. This is normal condition for used plug,let alone a 100k plug used with high sulphur petrol.
Nothing to worry about.

 

[CharBaby]

Originally Posted By: chrisri
Originally Posted By: Char Baby
On my wifes '01 Lesus RX-300 w/93K miles, the plugs look sort'a like this in the pic but, with a bit more white-ish residu(but, not ashey) on the center electrode. Mine look more like calcium deposits on only one side of the center electrode. This is the closest pic I can fine:

http://i465.photobucket.com/albums/rr14/Corysez/IMG_2460.jpg


If it looks like this it's good. This is normal condition for used plug,let alone a 100k plug used with high sulphur petrol.
Nothing to worry about.


Without being flakey or ashey, my color is a bit white-er and a little more of it!

 

[SwampSurvivor]

My Focus came from the factory with iridium plugs good for 100K miles. I'm sure the car would still be running at 100K miles with them, but I changed them out at 36K.

The car gained some power back for sure. There were hills that I could go up in OD when the car was new that I had to start dropping it into 4th gear to make it up. After replacing the 36K mike spark plugs with new ones, the car had its power back.

 

[Kira]

I gotta ask, are all the iridium plugs 100K? Is there a chart somewhere?

Are plugs categorized by the publicized material?

30K for copper core
50K for something else
100K for something else

I just would like to avoid the waste of over-changing or causing bad operation by "under-changing".

Kira

 

[KitaCam]

Originally Posted By: Kira
I gotta ask, are all the iridium plugs 100K? Is there a chart somewhere?

Are plugs categorized by the publicized material?

30K for copper core
50K for something else
100K for something else

I just would like to avoid the waste of over-changing or causing bad operation by "under-changing".

Kira


No.... Some ("performance") plugs are rated for 60k miles while "long-life" iridium plugs (typical of OEM) last 120k miles...basically once or twice in the life of most cars...

 

[chrisri]

All spark plugs are copper core. Well almost all . Standard ones that people call copper are infact nickel alloy tip plugs.
These last up to 40k km. Platinum plags can go to 100k km depending on engine . Iridium last even longer.The cheapest nickel alloy will perform same as platinum/ iridium spark plugs just won't last as long.

 

[ARCOgraphite]

All plugs are copper core (or equivalent) The electrode(s) can be a steel alloy, Inconel / monel with or w/o cu core or precious metal (Ir, Pt) IMO fine wire Ir should be the go-to plug for COP systems; then, dual precious electrode pill for lost spark. DIST systems are more flexible and can get by with good Inconel strap plugs.

 

[stockrex]

any deposit on the plug indicate dirt coming in. I have ngk plats from my honda after 100k miles, they look pretty consistent and without any deposits. I will post pics if I can dig it up.

 

[chrisri]

Originally Posted By: KitaCam
Originally Posted By: Kira
I gotta ask, are all the iridium plugs 100K? Is there a chart somewhere?

Are plugs categorized by the publicized material?

30K for copper core
50K for something else
100K for something else

I just would like to avoid the waste of over-changing or causing bad operation by "under-changing".

Kira


No.... Some ("performance") plugs are rated for 60k miles while "long-life" iridium plugs (typical of OEM) last 120k miles...basically once or twice in the life of most cars...


Performance plugs use more fragile copper wire and tip for stronger spark. Thinner wire and tip will reduce resistance so spark will be stronger. This is why they do not last as long.

 

[Astro14]

Originally Posted By: chrisri

Performance plugs use more fragile copper wire and tip for stronger spark. Thinner wire and tip will reduce resistance so spark will be stronger. This is why they do not last as long.


Uh...no.

All plugs use copper cores for good conductivity. The variances are in: electrode material, heat range (insulator length), and gap.

Harder/higher temp electrode materials last longer. Iridium has the highest melting point, then platinum, then the nickel steel of "copper" plugs.

Gap and temp range vary by application. Air is resistant to electricity, so a larger gap = more resistance and larger spark.

As far as life, that depends on application as well. I've seen 100K Iridium plugs that had no electrode left. None. How the engine ran with a gap at least twice as large as designed is beyond me, but it sure ran better with new plugs.

Even with Iridium tips, my Volvos show noticeable wear at 30K and run better with new plugs changed at that interval.

Mercedes plugs for the S600, also Iridium, are supposed to be changed at 100K...but I won't wait that long...

 

[hypervish]

The RX300 plugs are good for 120k miles. I changed mine at 160k miles and they looked great, could have easily done 200k.

 

[4wheeldog]

The Denso iridium plugs that I took out of my Tacoma w/70k miles had a gap 3X the original. But they were working fine. Most of those miles were towing, so definitely severe service.

The 60k NGK Iridiums I took out of my gently used Subaru looked just like the ones I took out of the box and put in. No visible wear, gaps very near original, and barely discolored.

(I believe 60k is as long as I will leave original plugs in, because I fear corrosion causing them to become "One with the head".)

After the first change, I don't worry as much, since I know they have anti seize on them that will last.

 

[Boss302fan]

Originally Posted By: hypervish
The RX300 plugs are good for 120k miles. I changed mine at 160k miles and they looked great, could have easily done 200k.


I agree. If they look great why change them? If they look almost like new, then it does not make sense to change them.

 

[chrisri]

Originally Posted By: Astro14
Originally Posted By: chrisri

Performance plugs use more fragile copper wire and tip for stronger spark. Thinner wire and tip will reduce resistance so spark will be stronger. This is why they do not last as long.


Uh...no.

All plugs use copper cores for good conductivity. The variances are in: electrode material, heat range (insulator length), and gap.

Harder/higher temp electrode materials last longer. Iridium has the highest melting point, then platinum, then the nickel steel of "copper" plugs.

Gap and temp range vary by application. Air is resistant to electricity, so a larger gap = more resistance and larger spark.

As far as life, that depends on application as well. I've seen 100K Iridium plugs that had no electrode left. None. How the engine ran with a gap at least twice as large as designed is beyond me, but it sure ran better with new plugs.

Even with Iridium tips, my Volvos show noticeable wear at 30K and run better with new plugs changed at that interval.

Mercedes plugs for the S600, also Iridium, are supposed to be changed at 100K...but I won't wait that long...


And were did i wrote that all plugs do not use copper core? Read my previous post.

 

[hypervish]

Here's a picture of my plugs at 160k miles, sorry for the horrible picture quality...And, my paint is in much better condition now! LOL

 

[BurrWinder]

Originally Posted By: stockrex
any deposit on the plug indicate dirt coming in. I have ngk plats from my honda after 100k miles, they look pretty consistent and without any deposits. I will post pics if I can dig it up.


No, that's not true. Deposits can come from fuel additives, oil blowby burning off ( ashy residue ) Carbon from fuel, coolant residue getting into cooling system (intakes, head gaskets,etc)
does not have to be anything at all related to "dirt" getting into chamber.