Oil on #3 plug
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Oil on #3 plug
Just Changed the plugs on dads speedster, engine is a 58 (68167) and the #3 plug had some oil on it, all others looked ok. Would this be caused by bad rings? Or Maybe carbon and oil?
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- Thomas Sottile
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Re: Oil on #3 plug
The oil could be caused by a number of things , Bad plug , bad plug wire , head gasket leake bad rings or just lack of driving.
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Re: Oil on #3 plug
Guides. Head gasket leak????
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Re: Oil on #3 plug
It's not a great picture(can't blow it up), but the plug looks oily and if so then it's usually rings or guides. Do a leak down test.
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Re: Oil on #3 plug
See below; fixed
Last edited by Ron LaDow on Fri Nov 27, 2015 11:11 pm, edited 1 time in total.
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Re: Oil on #3 plug
I was gonna suggest that also, but it won't tell you anything about guides. Any way to check those other than disassembly? I can't think of anything reliable.C J Murray wrote: Do a leak down test.
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Re: Oil on #3 plug
A leak down might eliminate ring problems as a cause and bad guides can expose themselves as valve leaks since they are not aligned correctly on the seats. In actual truth Ron is correct to suggest taking the engine apart for inspection because tests don't always reveal the problem. If the plug is oily I would remove the heads and have them rebuilt. If a problem is found at that cylinder and if there is no cylinder scoring then I might just put it back together but it might be wise to take the cylinders to the machinist also to have them measured for wear.Ron LaDow wrote:I was gonna suggest that also, but it won't tell you anything about guides. Any way to check those other than disassembly? I can't think of anything reliable.C J Murray wrote: Do a leak down test.
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Re: Oil on #3 plug
Did it take years for the plug to get that way, or fairly quickly?Was it still running decently when you changed the plugs? If so, maybe the engine is getting a little tired but still useable for now. I have seen plenty of plugs like that from cars that generally ran OK for a long time, I doubt if it is anything leading you to a major failure, if it isn't rattling and isn't using lots of oil.
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Re: Oil on #3 plug
Thanks every one. It probably took a while to get that way, since the car is not drivin that much. It doesn't us oil as far as I can tell. I'll keep checking on it periodically. After I get the carbs back on. Got some other plans for car before I can tear engine down.
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Re: Oil on #3 plug
It's kind of hard to see in your photo but it doesn't look like wet oil, just mostly carbon with a little oil mixed in. If you just installed new plugs I'd drive it for a few miles and pull the #3 plug again. If not I'd install a new set of plugs and repeat. Your mixture might be a little rich and that will soot up the plugs. And of course a compression test will tell you about how well the rings are sealing.David Kirby wrote:Just Changed the plugs on dads speedster, engine is a 58 (68167) and the #3 plug had some oil on it, all others looked ok. Would this be caused by bad rings? Or Maybe carbon and oil?
Cliff Hanson
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