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Clean oil at the base of the spark plug


48ply1stcar

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The car has been running fine, but recently (twice) I have looked at the engine before driving and found clean oil around the base of the 3rd spark plug.

Tomorrow (6-25) I going to check the head bolts next to that plug and see if any need to be touqued.

Photo0447.jpg

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Maybe a leak from the oil bath filter?

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Our car runs fine, too, and does the same thing once in a while.  Although I find it a bit strange that it's only #3, I've never worried about tracking it down, and all the plugs are torqued down correctly. But it's not the air filter, ours does not have an oil bath air filter.  Perhaps some blow-by through the valve guides, and it's #3 because it's closest to the intake/carb?  I know the valves are worn.

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12 hours ago, maok said:

Maybe a leak from the oil bath filter?

I use a paper filter. so I wonder if it's seeping from a head bolt and it's not really effecting the engine oil level.  I just thought that instead of typing this I need to get off my but and get outside before it gets in the 80s today.

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Hopfully I found it, the spark plug could have been tighter and I couldn't budge the head bolts.

1 hour ago, Merle Coggins said:

There's no oil up in the head, or anywhere near the head bolts. Anything coming through the head bolts would be coolant. 

Merle you are so right, where is my head.  I guess that working on and off the same car for 52 years has fried my brain.  Also, maybe it's nice to know that the compression in my re-built engine can push clean oil through a loose spark plug.

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18 hours ago, Sam Buchanan said:

Seems that if there is enough raw oil in the combustion chamber to push past a loose spark plug that you would have severe plug fouling problems...... 

I thought that too, but the sparkplug looked good.  Looking forward to a test drive on a cool morning.

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1 hour ago, 48ply1stcar said:

I thought that too, but the sparkplug looked good.  Looking forward to a test drive on a cool morning.

 

In that case you should be safe to assume the oil didn't come from the cylinder.

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  • 2 weeks later...
On 7/5/2020 at 8:31 AM, squirebill said:

Did you ever get this figured out?

I pulled a couple of plugs and discovered two things.  The plug with the oil was a Rj12YC and other five are RJ12C.  That shouldn't make adifference.  The five plugs look great with a ash/gray color.  The one plug looked unsed but dirty.  I measured the resistance of the bad plug and came up 1.00, max resistance? Maybe the plug never worked or stopped working.  Bought a spark plug today, didn;t get back to the car yet.

The car runs so well now, I'm excited to try driving with 6 cylinders.

Edited by 48ply1stcar
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So is the thinking the leaking plug was not firing  and somehow allowed crankcase oil to come past all the piston rings through the leaky plug and end up in the spark plug well? For all of this to happen I would think you have more problems than just a bad plug.  Will look forward to the result of the plug replacement.  Please keep us advised.  This is the kind of thing that happens and makes you go "Huh, never saw that before".  Regards.

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Squirebill, maybe the tiny amount of oil that coats the cylinder wall during the lubrication process builds and leaks around the sparkplug because it's not burn during combustion when the sparkplug fails to fire.  Replaced the plug today, tested the plug on the top of the block and pushed the starter button.  It Sparked, went for a ride and really couldn't tell the difference.  I guess it ran so well with 5 cylinders that 6 cylinders is just a bonus.  I check for oil later. 

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17 minutes ago, 48ply1stcar said:

maybe the tiny amount of oil that coats the cylinder wall during the lubrication process builds and leaks around the sparkplug because it's not burn during combustion when the sparkplug fails to fire. 

 

I think the rings are there to keep oil from getting to this area ... so the oil on the plugs is a secondary problem because the rings are not sealing.

So the leaking rings are the first issue, fouling out the spark plug is the second issue, fresh oil leaking pass the plug washer is the 3rd issue?

Might be a time to run a compression check on the engine ... plugs are cheap and a few extra in the glove box is never a bad idea.

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Perhaps it was not oil but coolant. The clear colour would be the give away.thick and syrup like just means the water evaporated out of it.  
 

also have to mention, i spilled coolant on my engine (cold) and there was some around a few spark plugs. Guess they werent sealing right, when i fired it up a couple were bubbling. Pulled the plugs and cleaned the sealing surface and gived em a lil extra torque. 

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3 hours ago, Plymouthy Adams said:

IS THE OIL REOCCURING?  if not.....give it up...else I will tell your wife to oil three plugs next time...

I am supposed to go pay him a visit.....

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