uneven combustion spark plug diagnosis needed
09-15-2008, 01:04 PM
#1
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uneven combustion spark plug diagnosis needed
Desiring diagnosis or advice....
I pulled two plugs yesterday and found a distinct line of mild carbon attached to exactly half of the ceramic cathode. Makes it look like the moon at half phase. (See blurry photos...)
Can anyone diagnose this as either an issue or normal?
Feel free to make spark plug recommendations as well. These are Bosche. I've been told NGK are better these days and that Bosche are not as good lately. I am naive so please advise without turning this into another spark plug loyalty debate. My car is a 1984 stock model. I do not race but enjoy a 'spirited' drive. I also would not mind replacing the spark plugs more often if there is a plug out there that performs better but suffers wear faster.
All Best,
Allen in Allentown, PA
I pulled two plugs yesterday and found a distinct line of mild carbon attached to exactly half of the ceramic cathode. Makes it look like the moon at half phase. (See blurry photos...)
Can anyone diagnose this as either an issue or normal?
Feel free to make spark plug recommendations as well. These are Bosche. I've been told NGK are better these days and that Bosche are not as good lately. I am naive so please advise without turning this into another spark plug loyalty debate. My car is a 1984 stock model. I do not race but enjoy a 'spirited' drive. I also would not mind replacing the spark plugs more often if there is a plug out there that performs better but suffers wear faster.
All Best,
Allen in Allentown, PA
09-15-2008, 03:09 PM
#3
Rennlist Member
normal. the spray of the gas and its additives does this, and it can color many parts of the plug.
all the plugs see a pretty lean and clean condition when cruising at part throttle most of the time, thats why they are so hard to read on a street car. you can get a general idea, based on wear or serious deposits.
mk
all the plugs see a pretty lean and clean condition when cruising at part throttle most of the time, thats why they are so hard to read on a street car. you can get a general idea, based on wear or serious deposits.
mk
09-15-2008, 10:13 PM
#5
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Thank you for the quick responses. I was hoping that this was not an fuel injector issue.
Are platinum coated plugs really not so good to use? Is the platinum coating to protect a copper anode underneath from heat deterioration or is there a performance reason? Has anyone any experience with silver anode plugs? Since silver is the best conductor of electricity, it seems like these would be a logical good choice. So many factors come into play so i must rely on other people's experience and knowledge.
Really opening the floor here on a subject that has probably been discussed to death. I will research the archives but feel free to offer advice here again too............
Are platinum coated plugs really not so good to use? Is the platinum coating to protect a copper anode underneath from heat deterioration or is there a performance reason? Has anyone any experience with silver anode plugs? Since silver is the best conductor of electricity, it seems like these would be a logical good choice. So many factors come into play so i must rely on other people's experience and knowledge.
Really opening the floor here on a subject that has probably been discussed to death. I will research the archives but feel free to offer advice here again too............
09-15-2008, 11:37 PM
#6
Team Owner
It seems that the best plug is the least expensive, WR7DC about 1.99 at autozone.
Use some anti seize when you install them and check the gaps of all the plugs you install
Use some anti seize when you install them and check the gaps of all the plugs you install
09-16-2008, 12:57 AM
#7
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X2...and try to blow the plug hole out with compressed air before you remove the plugs. Even with the tight fit of the seals i have no idea how bits of dirt etc get in there. Watch your eyes and ears.
