This is from the cylinder that is second closest to the firewall. I end up needing a new plug every 10 thousand miles. This plug has only about 8 thousand miles.
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carbon fouling
maybe a leaky injector or intake valve stem seal?1989 cirrisblau-metallic 325i -
It appears part of the insulation around the electode has disintegrated.Comment
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That doesn't look like carbon fouling. Way to white. Looks more like pre-ignition problems.Comment
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That is what my brother said. What causes it?Comment
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Well, I have some new info. I pulled all the plugs:
#1. clean
#2. clean3
#3. white deposits and part of insulator broken
#4. just replaced, but the old one had white deposits and broken insulator
#5. replaced last year and now has white deposits
#6. clean
The plugs and wires have about 60k on them.Last edited by clydesdale; 03-02-2010, 12:13 PM.Comment
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Pre ignition, cross firing- Incomplete ignition is what my book says- Your pic looks just like itComment
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I am unsure of the cause. Any ideas?Comment
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I do not think it is just a simple plug change. One of the plugs has been changed twice during that time because the cylinder stop firing. There are 3 plugs in a row that have insulator damage, the other 3 plugs are fine.
OK, I have a minor update. I did not do the compression test yet, but I did replace all the spark plugs. The stumble is now completely gone. The car drives great. But, obviously I know the problem did not go away. So, does this change anyones potential diagnosis? I know it is not one single injector anymore, as there are 3 plugs that were screwed up. All 3 cylinders are in a row, 3,4,5. I am hoping to get a compression test this weekend or next.Comment
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If I remember right, the injector harness is split up into 2 banks of 3 cylinders (someone correct me if I am wrong). I would check the harness for cylinders 3, 4 and 5 and see if there is anything obviously wrong like missing insulation on wires.Comment
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