The Ford Barn

rivcokid · 03-06-2019, 07:37 PM

Hi all - I decided to change out the spark plugs on my 1931 roadster because I now know that it's been sitting for a few years. All were pretty black, but the No. 3 plug (from the front) had oil on the threads and on the spark portion of it. Not a lot, but a noticable amount. Am I looking at a head gasket replacement now? There doesn't seem to be any problem with the way it drives - but now I'm concerned. Thanks!!

WHN · 03-06-2019, 08:08 PM

Just replace the plugs and cross your fingers.

You might not have to fix something that isn’t broken. Enjoy.

1crosscut · 03-06-2019, 08:18 PM

Fire it up and run it for 20 miles and then take a look at them. If it hasn't run for a long time condensation could be making things look worse than it looks.

30 Closed Cab PU · 03-06-2019, 10:41 PM

Hope I am not asking silly questions, just do not know any better. A Bad head gasket and oil on the spark plugs? Are there oil passages in the head, or on top of the Block? Or would this indicate ring/valve issues?

eagle · 03-06-2019, 10:57 PM

Is it exhausting some blue smoke? Wore rings can cause oil burning, if you are using synthetic oil it won't burn in the combustion chamber as much as regular oil and can cause oil in the cylinder and on/around the spark plugs. If it isn't causing the plugs to foul it can go for a long, long ways yet before anything needs to be done. Do a compression check on the cylinders, you may notice that one a bit lower.

Werner · 03-07-2019, 02:37 AM

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Good morning,

do it so like Dave wrotes.
Switch off the hot engine with very short idling-time and check the spark plugs. Dry dark brown to light brown is good.

Do not screw in the down cooled plugs end-firmly in the hot cylinder head!

(I use modern NGK Iridium with adapters.)

Tom Wesenberg · 03-07-2019, 08:14 AM

Plugs don't go bad from setting, so that's the last thing I'd change when trying to start an engine. The plugs fire easier when you have a sharp edge on the center electrode, so if it's worn rounded, then file it flat.

Brian in Wheeling · 03-07-2019, 08:28 AM

No oil passages in the head or on top of the block. Likely (IF) you have a problem it's going to be a ring problem or possibly worn/loose intake valve guide IMO. Do like others have said and just run it awhile and then recheck to see if actual oil is present. If so, could use a hotter plug till you get around to fixing it.
Brian

rivcokid · 03-07-2019, 08:46 AM

Thanks all! I'll give these ideas a try when it quits raining!

Railcarmover · 03-07-2019, 08:55 AM

Do not use irridium or platinum plugs with point based ignition systems,they dont handle deviations in output,they are designed for electronic systems that have stable output.Even with electronics electrodes fail and break off,irridium and platinum raise hell with steel and aluminum.

Bob Bidonde · 03-07-2019, 09:35 AM

Whenever the head gasket is suspect, do a compression check so you can base your decision on factual data.

cjkohnast · 03-07-2019, 09:39 AM

Old mechanic taught me long time ago. IF IT ANGHT BROKE DONT FIT IT.

Railcarmover · 03-07-2019, 10:39 AM

Old cob mechanic I worked with had morning shift,the crews would come in and get their trucks..drivers would come up to him and say they "found" something..he would point a crooked finger and squint his eye.." you find it? You fix it!"

03-06-2019, 07:37 PM	#1
rivcokid Senior Member Join Date: Sep 2018 Location: Riverside, CA Posts: 171	Oil on Spark Plug Hi all - I decided to change out the spark plugs on my 1931 roadster because I now know that it's been sitting for a few years. All were pretty black, but the No. 3 plug (from the front) had oil on the threads and on the spark portion of it. Not a lot, but a noticable amount. Am I looking at a head gasket replacement now? There doesn't seem to be any problem with the way it drives - but now I'm concerned. Thanks!!

03-06-2019, 08:08 PM	#2
WHN Senior Member Join Date: Mar 2017 Location: Connecticut Shoreline Posts: 1,821	Re: Oil on Spark Plug Just replace the plugs and cross your fingers. You might not have to fix something that isn’t broken. Enjoy.

03-06-2019, 08:18 PM	#3
1crosscut Senior Member Join Date: Feb 2011 Location: Lincoln, Nebraska Posts: 1,907	Re: Oil on Spark Plug Fire it up and run it for 20 miles and then take a look at them. If it hasn't run for a long time condensation could be making things look worse than it looks. __________________ Dave / Lincoln Nebraska

03-06-2019, 10:41 PM	#4
30 Closed Cab PU Senior Member Join Date: Aug 2018 Posts: 2,332	Re: Oil on Spark Plug Hope I am not asking silly questions, just do not know any better. A Bad head gasket and oil on the spark plugs? Are there oil passages in the head, or on top of the Block? Or would this indicate ring/valve issues?

03-06-2019, 10:57 PM	#5
eagle Senior Member Join Date: Aug 2011 Location: Eagle Bend, MN Posts: 2,025	Re: Oil on Spark Plug Is it exhausting some blue smoke? Wore rings can cause oil burning, if you are using synthetic oil it won't burn in the combustion chamber as much as regular oil and can cause oil in the cylinder and on/around the spark plugs. If it isn't causing the plugs to foul it can go for a long, long ways yet before anything needs to be done. Do a compression check on the cylinders, you may notice that one a bit lower. __________________ "There are some that can destroy an anvil with a teaspoon and shouldn't be allowed to touch anything resembling a tool."

03-07-2019, 08:14 AM	#7
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Oil on Spark Plug Plugs don't go bad from setting, so that's the last thing I'd change when trying to start an engine. The plugs fire easier when you have a sharp edge on the center electrode, so if it's worn rounded, then file it flat.

03-07-2019, 08:28 AM	#8
Brian in Wheeling Senior Member Join Date: May 2010 Location: Wheeling, WV - U.S.A. Posts: 241	Re: Oil on Spark Plug No oil passages in the head or on top of the block. Likely (IF) you have a problem it's going to be a ring problem or possibly worn/loose intake valve guide IMO. Do like others have said and just run it awhile and then recheck to see if actual oil is present. If so, could use a hotter plug till you get around to fixing it. Brian

03-07-2019, 08:46 AM	#9
rivcokid Senior Member Join Date: Sep 2018 Location: Riverside, CA Posts: 171	Re: Oil on Spark Plug Thanks all! I'll give these ideas a try when it quits raining!

03-07-2019, 08:55 AM	#10
Railcarmover BANNED Join Date: Apr 2017 Location: Sacramento Posts: 1,262	Re: Oil on Spark Plug Do not use irridium or platinum plugs with point based ignition systems,they dont handle deviations in output,they are designed for electronic systems that have stable output.Even with electronics electrodes fail and break off,irridium and platinum raise hell with steel and aluminum.

03-07-2019, 09:35 AM	#11
Bob Bidonde Senior Member Join Date: May 2010 Location: Long Island, NY Posts: 3,464	Re: Oil on Spark Plug Whenever the head gasket is suspect, do a compression check so you can base your decision on factual data. __________________ Bob Bidonde

03-07-2019, 09:39 AM	#12
cjkohnast Senior Member Join Date: Jan 2017 Posts: 357	Re: Oil on Spark Plug Old mechanic taught me long time ago. IF IT ANGHT BROKE DONT FIT IT.

03-07-2019, 10:39 AM	#13
Railcarmover BANNED Join Date: Apr 2017 Location: Sacramento Posts: 1,262	Re: Oil on Spark Plug Old cob mechanic I worked with had morning shift,the crews would come in and get their trucks..drivers would come up to him and say they "found" something..he would point a crooked finger and squint his eye.." you find it? You fix it!"