StructEngineer Posted June 23, 2008 Share Posted June 23, 2008 Changed out my NGK V power spark plugs on my 2002 Forester. The drivers side rear cylinder plug has very small speckles of green on one face of the electrode arm. Has anyone seen this before? I'm assuming coolant. Would you worry and/or do anything? 88,000 mi. If you can guide me how to post a pic I can show a closeup of the plug. Quote Link to comment Share on other sites More sharing options...
keltik Posted June 23, 2008 Share Posted June 23, 2008 Oxidised copper from the core of the electrode? Thats all i can think of.... Quote Link to comment Share on other sites More sharing options...
audio_file Posted June 23, 2008 Share Posted June 23, 2008 easiest way to post detailed pics is to host them somewhere else and link to it . . . i.e. photobucket.com if it's too much of a hassle, pm me and i'll host it for you on my photobucket acct . . . i've got to see this . . . chris Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted June 23, 2008 Share Posted June 23, 2008 Oxidised copper from the core of the electrode? Thats all i can think of.... agree, copper is the only part of a spark plug that will oxidize with a green color. Quote Link to comment Share on other sites More sharing options...
Buick350X Posted June 23, 2008 Share Posted June 23, 2008 Them newer fancy small electrode plugs were designed on purpose like that for newer cars that run lean as a popcorn fart to make the EPA happy. So the electrode will just vaporize, insted of having enough material to let a gobblet of metal to melt lose and jam up in a ring or valve............ Far as NGK goes that are pretty much banded in the motorcyle world as the quality of the manual suggested standard NGK bike plug sucks. They foul, fail and are down right fussy junk. And a simple change to bosche or autolite platinums often gives folks a feeling a a whole new bike, let alone plugs that work how they should. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 23, 2008 Share Posted June 23, 2008 [...]The drivers side rear cylinder plug has very small speckles of green on one face of the electrode arm.[...] A picture could certainly help, but less than 1,000 words might do in its place. Some Q's: 1) Can we assume the other three plugs look "normal"? 2) Are the "speckles" hard (ceramic-like) and well-adhered, or soft and easily removed? 3) Are they rough (matte) or smooth (glossy) in appearance? ...and lastly... 4) Do you think I'll know what they are if you answer 1 through 3? Quote Link to comment Share on other sites More sharing options...
audio_file Posted June 23, 2008 Share Posted June 23, 2008 4) Do you think I'll know what they are if you answer 1 through 3? " . . . check yes 'er no . . ." chris Quote Link to comment Share on other sites More sharing options...
Olnick Posted June 23, 2008 Share Posted June 23, 2008 4) Do you think I'll know what they are if you answer 1 through 3? Cracked me up!!! Good one OB99W. Quote Link to comment Share on other sites More sharing options...
StructEngineer Posted June 23, 2008 Author Share Posted June 23, 2008 Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 23, 2008 Share Posted June 23, 2008 " . . . check yes 'er no . . ." Cracked me up!!! Good one OB99W. Thanks, I'm glad it was appreciated. We now return you to the usually-more-serious OB99W. Quote Link to comment Share on other sites More sharing options...
StructEngineer Posted June 23, 2008 Author Share Posted June 23, 2008 The other plugs look like this.. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 23, 2008 Share Posted June 23, 2008 As to the pictures: The difference in lighting of the two plugs makes it a bit difficult to comparatively "read" them. Electrode wear on both seems reasonable, insulators look good, etc. The temperature range of the plugs seems to be about right for the type of driving being done. If we ignore the "speckles", the #4 plug appears similar to the other one, within the limitations of the pics. Can we see a picture of #4 with lighting like the other one? If not, does #4 have similar-looking deposits (carbon, etc.) on the inner surfaces of the plug shell to the other? Keep in mind that due to the wasted spark arrangement, two of the plugs are fired with "reversed" polarity. Also, minor differences in fuel distribution and combustion chamber temperatures can change the way plugs look even in a well-running engine. Responses to my previous questions (please feel free to ignore the fourth one), might provoke further comments from me. Quote Link to comment Share on other sites More sharing options...
StructEngineer Posted June 23, 2008 Author Share Posted June 23, 2008 Having fun with my new camera! Updated the first pic, note the central electrode is pitted and not smooth. Other plugs look normal The speckles are hard ceramic like and well adhered. The speckles aren't shiny. and if it makes any difference the photo in post #11 is the rear passenger side. Quote Link to comment Share on other sites More sharing options...
keltik Posted June 24, 2008 Share Posted June 24, 2008 Well they are obviously well worn plugs. So my bet is still on the electrode degrading and allowing some of the copper core to vapourise. Maybe during gapping the plug the outer coating was damaged in these areas...or maybe its just old. I think the best test will be to see what the new ones look like in a couple thousand miles. Do you use any fuel additives? Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 24, 2008 Share Posted June 24, 2008 Having fun with my new camera! Updated the first pic, note the central electrode is pitted and not smooth[...] and if it makes any difference the photo in post #11 is the rear passenger side. Pic of #4 is much better now. Pitting noted -- #3 (rear pass) and #4 (rear drvr) are on opposite sides of the same coil in the pack, and receive reversed spark polarity with respect to each other. The electrode that wears most (center versus ground) is dependent on that spark polarity. Also due to polarity, some types of deposits will tend to form on one electrode or the other. I think I see a bit of the deposits in question on the side of the center electrode of plug #3. I suspect you'll notice a difference between #1 and #2 as well, although perhaps not to the same degree. As I mentioned previously, slightly differing cylinder conditions isn't uncommon. Unless the engine is otherwise giving reason to suspect a problem, I wouldn't be too concerned. A reference for reading plugs can be found at: http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp?mode=nml For green deposits, see "Erosion, Corrosion and Oxidation". Many of the plugs shown give good reason to investigate further. EDIT: By the way, some ideas for posting pics: http://www.ultimatesubaru.org/forum/showthread.php?t=83977 Quote Link to comment Share on other sites More sharing options...
bulwnkl Posted June 27, 2008 Share Posted June 27, 2008 The specks are metallic deposits which are there from one of: Fuel component/additive, Motor oil component/additive, maybe a coolant component/additive. They are not spark plug conductor vaporization deposits, IMO. Quote Link to comment Share on other sites More sharing options...
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