Silver ring on the spark plug?
 

Hmm...Just looking at some plugs and I noticed a silver ring around the inside. Ive never noticed that before...And I didnt see it on any others ( At least, I dont remember seeing it ).


Would leaded fuel leave a deposit like that?

Heres a pic.
http://adamlewis88.homestead.com/files/Stupid_012.jpg

bump?

not mine, mine r always caked up with some brown shit when i change them


-Shawn (that reminds me i need to change them)

As far as I can remember, theyve always looked like that MINUS the silver ring.

Can leaded gas leave a deposit like that on the plug? I know it leaves a deposit on the exhaust tips...

i didn't know they still sell leaded gas

how many miles r on the plugs?

-Shawn

i have nothing important to add to this thread, but....why are you worried about leaded gas?

just curious.

its not leaded gas. They pretty much dont sell that anywhere, unless u filled up at a race track or somthing. and it would destroy your O2 sensor and cats....
thats just an ash deposit. just use a wire brush and clean it off.

That's one clean plug - how many miles?? Mine also have the 'ring' along with brownish deposits (from gas additives) although if I look at mine I wouldn't say its from deposits but rather a wear surface, likely from where the spark makes contact.

Henrik
87TII

Hello and welcome to a normal looking used spark plug..

Just a little wore out..


The center to the outer edge of the area you saw is where the gap is measured. so if it is not a flat squared edge on the center electrode its wore out.

I remember someone saying they removed that particular ring on all 4 plugs after seeing, while the Motor was apart, that the SP's actually go deeper without knicking the Apex Seal.

He hypothesized a more Intense spark Is created by them being closer Into the Combustion Chamber.:confused:

Mazda designed It like that so I leave It as Is.

*edit* sorry, thought you were talking about ring (washer). Didn't even look at pic.:)

Never seen that before, but because it's a uniform circle, I'd think it has something to do with the spark and a reaction, not anything catastrophic.

That electrode looks good. When I changed my plugs, the lead electrodes were worn down to little nubs. The trailing plugs looked okie dokie though. I just had brown scale on the conductor material. Yours is really clean, you may be burning lean or something, or there's coolant is giving yer housings the ol' steam clean. Hope it's nothing big.