What does this Brown Crust on Spark plugs mean?
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Bad link
Originally Posted By: DemoFly
Bad link
Thanks for that. Try now.
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OR THIS
http://s1072.photobucket.com/albums/w366/auditurbo/
Bad link
Thanks for that. Try now.
[/img]
OR THIS
http://s1072.photobucket.com/albums/w366/auditurbo/
I've had that before. Didn't affect performance one iota.
MolaKule
Staff member
Looks like a metal to cermaic seal gone bad.
Originally Posted By: MolaKule
Looks like a metal to cermaic seal gone bad.
This has happened on the StoCK NGK platinum plugs as well. But those plugs had 65k on them. These only have 10-15k at the max.
How can i avoid this on the next set of plugs? any ideas?
Looks like a metal to cermaic seal gone bad.
This has happened on the StoCK NGK platinum plugs as well. But those plugs had 65k on them. These only have 10-15k at the max.
How can i avoid this on the next set of plugs? any ideas?
Interesting. But this message board post below (posts #7 and #9) suggests that's simple rust from water accumulation in the spark plug hole. This dude in the link appears to have variations of such deposits on THREE of his Champion spark plugs, which clearly couldn't mean three defective plugs, so it's either oil, rust, or unicorn tears (I say the latter).
http://www.lxforums.com/board/f71/can-you-read-spark-plugs-186843/
http://www.lxforums.com/board/f71/can-you-read-spark-plugs-186843/
Originally Posted By: audia6
http://s1072.photobucket.com/albums/w366/auditurbo/
It's rust. Common and normal.
Spark plug internal seals are rarely absolutely perfect. Combustion chambers generate very high pressures; some of that pressure squeaks past the seals and makes such marks on the insulator. There's always water in combustion gases; since spark plug bodies are plain steel, the trapped water makes them rust inside a bit, and this rust eventually gets blown up onto the insulator.
No worries.
http://s1072.photobucket.com/albums/w366/auditurbo/
It's rust. Common and normal.
Spark plug internal seals are rarely absolutely perfect. Combustion chambers generate very high pressures; some of that pressure squeaks past the seals and makes such marks on the insulator. There's always water in combustion gases; since spark plug bodies are plain steel, the trapped water makes them rust inside a bit, and this rust eventually gets blown up onto the insulator.
No worries.
LOL, two pages of answers and each of them wrong.
Quote:
[Appearance]
Brown deposits on the insulator directly above the housing
[Results]
No impact on the spark plug performance
[Cause]
This occurs due to electrical stress in the air near the insulator. (This is not a spark plug gas leak, for which it is sometimes mistaken.)
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/troubleshooting/index.html
Quote:
[Appearance]
Brown deposits on the insulator directly above the housing
[Results]
No impact on the spark plug performance
[Cause]
This occurs due to electrical stress in the air near the insulator. (This is not a spark plug gas leak, for which it is sometimes mistaken.)
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/troubleshooting/index.html
Thats interesting. I am familiar with corona staining but it was always a dark smoky gray color to very light tan.
I wonder why the stain is so much darker? Boot material, silicone grease? Thanks for shedding a little more light on it.
This is how i remember the corona stains color.
http://www.ngk-sparkplugs.jp/english/techinfo/qa/q17/index.html
I wonder why the stain is so much darker? Boot material, silicone grease? Thanks for shedding a little more light on it.
This is how i remember the corona stains color.
http://www.ngk-sparkplugs.jp/english/techinfo/qa/q17/index.html
Originally Posted By: friendly_jacek
LOL, two pages of answers and each of them wrong.
Quote:
[Appearance]
Brown deposits on the insulator directly above the housing
[Results]
No impact on the spark plug performance
[Cause]
This occurs due to electrical stress in the air near the insulator. (This is not a spark plug gas leak, for which it is sometimes mistaken.)
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/troubleshooting/index.html
Thanks friendly_jacek for this good info.
That's how my original plugs looked like when I pulled them out, and come to think of it, every other plug that I pulled out had at least a bit of that residue.
LOL, two pages of answers and each of them wrong.
Quote:
[Appearance]
Brown deposits on the insulator directly above the housing
[Results]
No impact on the spark plug performance
[Cause]
This occurs due to electrical stress in the air near the insulator. (This is not a spark plug gas leak, for which it is sometimes mistaken.)
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/troubleshooting/index.html
Thanks friendly_jacek for this good info.
That's how my original plugs looked like when I pulled them out, and come to think of it, every other plug that I pulled out had at least a bit of that residue.
Originally Posted By: KrisZ
Thanks friendly_jacek for this good info.
That's how my original plugs looked like when I pulled them out, and come to think of it, every other plug that I pulled out had at least a bit of that residue.
Well, you learn something new every day.
I have in front of me right now 4 plugs, all of which have been in use in the same engine for the same length of time (2 years), and exhibit the same wear patterns on their electrodes. Three of them have corona discharge; the fourth has not a trace of it. I wonder why?
Thanks friendly_jacek for this good info.
That's how my original plugs looked like when I pulled them out, and come to think of it, every other plug that I pulled out had at least a bit of that residue.
Well, you learn something new every day.
I have in front of me right now 4 plugs, all of which have been in use in the same engine for the same length of time (2 years), and exhibit the same wear patterns on their electrodes. Three of them have corona discharge; the fourth has not a trace of it. I wonder why?
"Spark plug internal seals are rarely absolutely perfect. Combustion chambers generate very high pressures; some of that pressure squeaks past the seals and makes such marks on the insulator."
Links and/or evidence, please....
Links and/or evidence, please....
yep leaking. i have seen more that did than didnt.
Originally Posted By: morris
yep leaking. i have seen more that did than didnt.
So, why most plugs would be leaking if I may ask? Poor quality across all the brands? Wouldn't you see more leaking in turbo application?
yep leaking. i have seen more that did than didnt.
So, why most plugs would be leaking if I may ask? Poor quality across all the brands? Wouldn't you see more leaking in turbo application?
Did you try dielectric grease?
The plugs on the F250 (carb'ed 460), the SVX (flat 6), the various Mercedes V8'sand all the motorcycles don't ever look like this.
Cheers!
p.s. What's on the outside is not quite as important as what is on the inside, IMHO.
The plugs on the F250 (carb'ed 460), the SVX (flat 6), the various Mercedes V8'sand all the motorcycles don't ever look like this.
Cheers!
p.s. What's on the outside is not quite as important as what is on the inside, IMHO.
I don't think i ever saw one leak at the insulator, if i did i didn't know it.
I would think that if combustion chamber gases were leaking from the insulator there would be some damage to the bottom of the boot and maybe some noise or smell.
I really don't know just my thoughts on it.
I would think that if combustion chamber gases were leaking from the insulator there would be some damage to the bottom of the boot and maybe some noise or smell.
I really don't know just my thoughts on it.
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