Should I attempt to change spark plugs myself?

ghunt81

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Guess I'm the NKOTB & have to ask whet's the deal w/removing plugs on these S197 motors? I've wrenched on everything from a Rupp 5-hp minibike, 1940's farm tractors and diesel semi's...are these plugs prone to seizing in the threads?

For whatever reason Ford spec'ed a 2 piece "long reach" plug for the early 4.6 3V. So, it has a long nose that goes down through an opening in the head into the combustion chamber. Problem is that carbon builds up around the plug nose in this opening and causes the plug to be difficult to turn.

And this is where the 2 piece construction comes into play- the plugs tend to break off rather than just coming out, because the plug "nose" and the hex are two separate pieces.

I think if they'd just used a 1-piece plug from the factory, it probably wouldn't even have been an issue.
 

06 T-RED S/C GT

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For whatever reason Ford spec'ed a 2 piece "long reach" plug for the early 4.6 3V. So, it has a long nose that goes down through an opening in the head into the combustion chamber. Problem is that carbon builds up around the plug nose in this opening and causes the plug to be difficult to turn.

And this is where the 2 piece construction comes into play- the plugs tend to break off rather than just coming out, because the plug "nose" and the hex are two separate pieces.

I think if they'd just used a 1-piece plug from the factory, it probably wouldn't even have been an issue.

This was exactly the reason Ford revised the head design and went back to the traditional 12mm 1 piece design spark plug in 2008..
 

tjm73

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My 5.4 3V F-150 needed new plugs last summer. I paid to have them changed rather than risk breaking one myself. But I did run 2 bottles of seafoam through the fuel system before taking it in. The guy that did it has done a lot of them and has a real feel for it. He said he felt one starting to act like they do when they break and he back off on that one and came back to it and it came out. All 8 came out without breaking. He said the seafoam might have helped and certainly didn't hurt.
 

LordBritish

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My strategy is to go really slow.

I'm going to use seafoam deep creep and then crack them open 1/8 of a turn then let it sit overnight.

Then I'll try do another 1/8 (or 1/4) turn the next day.

I don't care if this takes me weeks !!

I've got another car to drive so no big deal.
 

RocketcarX

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How many miles are on the car? They say anything under 100k and you're in the clear for breakage, so far this has been true in my experience.
 

01yellerCobra

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My strategy is to go really slow.

I'm going to use seafoam deep creep and then crack them open 1/8 of a turn then let it sit overnight.

Then I'll try do another 1/8 (or 1/4) turn the next day.

I don't care if this takes me weeks !!

I've got another car to drive so no big deal.

IMO I wouldn't let it sit overnight. I pull the car in and start pulling the COPs. It sucks working on the engine when it's hot, but I think that's the secret. I used PB Blaster when I did mine. I've done a few sets and have only had one break. It was on an F150 with about 125K on it. I got too cocky on that one and tried to push it when I could feel it start sticking.
 

tjm73

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Wonder if the warm aluminum expands more than the plug material?
 

Sky Render

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Definitely use anti-seize. That should be a requirement on any spark plug. I used it on my Coyote motor when I put new plugs in.
 

BruceH

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Run it with two bottles of techron through the tank then when you are close to being out of fuel change the plugs on a warm not hot engine. Break them all loose a eighth to quarter of a turn then fill them up to the porcelain with deep creep. It is a decarbonizer. That is what makes the plugs stick. Let it sit over night then hit them with a impact.

Guess I'm the NKOTB & have to ask whet's the deal w/removing plugs on these S197 motors? I've wrenched on everything from a Rupp 5-hp minibike, 1940's farm tractors and diesel semi's...are these plugs prone to seizing in the threads?

It has to do with the head design. The plugs can become seized with carbon but it's not the threads, it's the barrel of the plug. HT (plug definer) stands for high thread. The plugs have a high thread and lower barrel. The barrel portion sits in the head and is prone to becoming seized by carbon build up.

I've never had an issue with them but then again I'm not the guy who really thinks a motor can go 100k without some sort of inspection or service. I'm from a long time ago when Kmart sold tune up kits and plugs didn't last more than 10k if you had to start your car when it was -20.
 

GallopingFord

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It all depends. I just swapped plugs myself, last week, on a 08 Explorer with the earlier head design and it had 132K miles - never changed. Extracted them all carefully and none broke.

However when our shop does these two-piece plugs, we always warn customers there is a risk that they may break and the labor involved in extracting them.
 
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teeje

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Just did mine with no issues. Ran to operating temp let it sit for a couple minutes and took them out with hand tools. No impact and d idnt break a single one

Sent from my SM-G955U using Tapatalk
 

LordBritish

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How much force is required to initially turn the plugs ?

Do the plugs typically break during the initial turn or later?

I heard that you should not exceed 35 ft-lb of force.
 

Phil1098

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How much force is required to initially turn the plugs ?

Do the plugs typically break during the initial turn or later?

I heard that you should not exceed 35 ft-lb of force.

Use whatever it takes, just don't turn them more than 1/8 turn initially to allow the solvent to run down the threads and onto the long tip.
 

LordBritish

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Use whatever it takes, just don't turn them more than 1/8 turn initially to allow the solvent to run down the threads and onto the long tip.

Thanks. I was afraid the plugs would break on that initial 1/8 turn.
 

Phil1098

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Thanks. I was afraid the plugs would break on that initial 1/8 turn.

You don't have a choice, if you don't break them loose, the solvent won't run down and do anything. It's a catch 22 for sure. The 1/8 reduces the risk but gives enough room for the solvent to work.
 

LordBritish

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Do I need to change the engine oil after changing my plugs?

Some say the carb cleaner (deep creep in my case) will mess up your engine oil.
 
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