seized sparkplugs

[Caasi]

What are the best ideas for getting a seized spark plug out?   289 engine. 

 

TY

[Jim Skelly]

Studebaker or FoMoCo?

[31nash880]

Marvel Mystery Oil from top. If it turns over some in there also. Will it run to heat it up?

[Bloo]

If this is a Ford engine with oversize tapered plugs, I would say a 1/2" drive spark plug socket and a really big breaker bar. Maybe a pipe. Watch what the bar or pipe is aimed at. It is going to let go with a bang.

Edited April 16, 2023 by Bloo (see edit history)

[Caasi]

44 minutes ago, Jim Skelly said:

Studebaker or FoMoCo?

FoMoCo

[Joe Cocuzza]

Heat,spray lube,heat again. Do this as often as needed while gradually trying to work the plug free.

Once you get the plug to turn a little then more heat,lube... and then tighten the plug,then loosen the plug, tighten the plug, loosen the plug....and continue to spray lube into the threads and work the plug back and forth (loosen/tighten). This will "clean" the threads of both the plug and the head of any rust/debris while decreasing the chances of the plug snapping off and/or stripping the head.

I had 2 plugs that I thought would never come out without snapping off (or damaging the head) but with patience, some heat and lube and the loosen/tighten method I was able to remove them cleanly.

[Frank DuVal]

Those 18mm tapered seat plugs should respond to a good soaking, like MMO (mentioned above), ATF, Kroil, etc, whatever you have.

 

I have not seen an aluminum head for a 289, this isn't one is it?

[John348]

1 hour ago, Frank DuVal said:

 

I have not seen an aluminum head for a 289, this isn't one is it?

Frank, I am not familiar with Fords but I was wondering the same thing, I would suggest that the heads are iron first.  

[Angelfish]

Penetrating oil and patience, that goes without saying.

 

I've had good luck with a cordless impact wrench.  Turn the power all the way down to the lowest setting and work on them a little bit at a time.  Oil, impact, oil, impact.  Might take a few days.

 

 

Edited April 17, 2023 by Angelfish (see edit history)

[Bloo]

What I think some people may be missing here is what kind of plugs a 289 Ford uses. They are 18mm (huge) with a tapered seat. There is no gasket. When they aren't stuck, they still let go with a big "SNAP!!!!" that sends a shock wave through your bones all the way to your shoulder. Sure, penetrating oil might help, and is a good idea. It might help break up some rust on the outside. Unfortunately it will probably never get all the way to the threads, because the taper is intended to seal and it does a really good job. The threads probably aren't stuck anyway. It's probably the taper. Plugs of this type are going to let go with a big bang, even if they were put in last week.

 

[28 Chrysler]

I had the same problem with a 1966 Comet in 1979 trying to get what might have been the original plugs.

I took a 1/2" drive beaker bar with a 2' cheater pipe. I think I broke at least half of the tops off.

They were the worst looking plugs I had ever seen.

[keiser31]

Sometimes trying to tighten them a tad prior to removal will break them loose.

[Akstraw]

We're curious.  Let us know when you get them out.

[dodge28]

I do not know what  is a 289. If the head is aluminium the plug could come off with some of the host metal with it.

[kgreen]

I've had to deal with this for years on my 289.  There is no breaker bar that will cleanly access the plugs on the smaller cars like the Mustang or falcon, etc.  The Galaxies and pickups have engine bay room and allow room to leverage a socket.  Against all advice I use an anti-seize compound.  It's not recommended because the spark plug gets its ground though the threaded portion of the plug.  

https://www.mcmaster.com/lubricants/electrically-conductive-antiseize-lubricants/

[Frank DuVal]

A 289 is a Ford engine. It could also be a Studebaker engine, but that was cleared up in post #5. 

 

Known as a Windsor and a Small Block Ford, this one is 289 cubic inches in displacement.

 

I can only find references to cast iron heads, so put on some penetrating oil and get a bigger wrench length! As stated above.

[Frank DuVal]

1 minute ago, kgreen said:

It's not recommended because the spark plug gets its ground though the threaded portion of the plug.  

Anti seize is conductive. The issue is getting it on the electrodes and shorting the plug. As they say for Brylcreem, a little dab will do you.😉

 

I would not worry about the plug grounding to the head, even oil pressure switches with pipe dope or Teflon tape on the threads will work (ground properly) as the metal threads will bite through most stuff.

[Bloo]

Anti-seize is fine on plug threads, just don't use too much. People make a big deal of it today because it can foul an oxygen sensor, but you won't find one of those on many 289 Fords. You never wanted anti-seize getting in the cylinder anyway as it could short out a plug. Moderation is key.

[60FlatTop]

I have a nice little 4 oz. hammer that has loosened up some really tight threads, ones already damaged with bigger tools. I just use it to constantly tap the stubborn part. On a 289 Ford I would break the porcelain tip off to give a good rap right on the metal part. Any light oil would be fine. The key is to rap it with a lot of wrist action like ringing a bell. Sharp ringing blows that resonate through the threads will do it. Just keep it up. Don't hit hard. Don't hit heavy or a dead blow, just keep hitting like a bell. You might take half an hour but when it loosens you will probably turn it out with your fingers.

 

I have experience doing this with all kinds of materials.

[dodge28]

I would break the ceramic and use a small flame torch and heat the plug.  Copper grease has copper in the grease to make it slippery and heat resistant all at the same time .It conducts electricity. Do not use around electrical connection. Cautiously use it on threads only. Very good for exhaust systems. Truckers use it for air brakes because of resistance to heat.