Motor Magazine, Jan '08

Trouble Shooter
by Karl Seyfert

January 2008. Carbon buildup can turn a routine spark plug change into a waking nightmare. These tips will help you avoid a disaster, or recover from one that's already occurred.

These spark plugs have a very long unthreaded ground electrode shield that extends below the threaded area of the plug. The plug's seat is also above the ground electrode shield. The shield reaches the rest of the way down to the combustion chamber. A side-to-side ground strap, rather than one or more side electrodes, is used, so the plugs do not require gapping. The ground strap looks like a basket handle. Autolite calls these Revolution HT (high thread) plugs.

Because the ground electrode shield is below the plug seat, carbon from the combustion chamber may accumulate between the shield and the cylinder head plug bore. The carbon may cause the plug to seize to the plug bore, so extreme caution must be exercised during spark plug removal. Engine temperature during this procedure is critical—not too hot and not too cold. Ideally, the engine should be warm to the touch. Run the engine to operating temperature, then allow it to cool until it reaches a comfortable working temperature.

Remove the coil-on-plug assemblies, then blow out the spark plug wells and surrounding valve cover area with compressed air. Back out the spark plugs, no more than 1 /8 to 1 /4 turn, then apply penetrating oil to fill the spark plug wells, to a level just above the jam nut hexes. Don't get carried away. Too much penetrant, or repeated soakings, may allow the penetrant to find its way into the cylinders and cause a hydraulic lock. Ford recommends a specific penetrant called AeroKroil that's marketed by Kano Labs ( www.kanolabs.com). If you've had success with another penetrant brand, use it. Allow the penetrant to sit for a minimum of five to ten minutes—longer if possible. Don't work the spark plug back and forth at this point.

After the penetrant has worked its magic, slowly remove the spark plug. It may protest by screeching, and high effort may be noticed. The expected removal torque should be about 33 ft.-lbs. and decrease as the plug comes out. If the plug feels tighter than that, stop! Try turning the spark plug back in by half a turn, then back out again. If the turning torque still seems high, repeat the back-and-forth rotation, while adding more penetrating oil to reduce the turning effort.

The important thing here is to take your time. Some have suggested using air or power tools to “shock” the plug loose. Ford advises against this practice and it sounds like good advice. Anything that applies too much torque to the plug is likely to break it in two (or more) pieces, and that's something that any right-thinking person would want to avoid.

If, despite your careful efforts, one or more spark plugs still break off during removal, all hope is not lost. The Ford TSB (06-15-2) that Terry mentioned covers the full procedure for removing broken spark plug pieces. We don't have the space to cover the entire removal procedure here, so we'll hit the highlights instead.

When a plug breaks, it may take all of the insulator with it, or a portion may remain behind inside the ground electrode shield. All of the insulator must be removed first, before removing the empty shell of the ground electrode shield. If there's enough to grab on to, use long-reach needle-nose pliers to remove the insulator. More soaking may be required.

If the insulator has broken off flush with the ground electrode shield, as it did for Terry, purchase a drill bit that's designed for glass, ceramic, concrete, etc. Add a 6-in. drill extension and a right-angle drill, then slowly drill out the insulator. A sharp punch can be used to break the insulator into pieces, but try to keep any of the debris from entering the combustion chamber. Vacuum the area around the ground electrode shield when you're done.

The next step involves a special tool (Rotunda Special Service Tool 303-1203) that threads into the ground electrode shield, then pulls it out of the head. This tool is available in the aftermarket as well through OTC. The inside bore of the ground electrode shield must be tapped first, before the special tool can do its thing. As before, a steady approach will give you the best chance of success. If you need any extra motivation, just keep telling yourself, “I don't want to remove those cylinder heads.”

When you're ready to install the new spark plugs, apply a film coating of high-temperature nickel antiseize lubricant (Motorcraft XL-2) to the ground electrode shield. Coating the electrode strap may cause a misfire. Do not apply lubricant to the threads and torque the plugs to 25 ft.-lbs. Thankfully, Ford changed the spark plug bore diameter slightly on later models, so this routine shouldn't be necessary on them.

 

Finally dove in and started the plug change today (2005 F150 82,000 miles). All went well on the driver side - there is no doubt that the 'Kroil works to dissolve the carbon on the sleeve. The 4 plugs were definitely coated in carbon and it was especially heavy at the sleeve-to-plug body joint.

Following the same, patient approach to the passenger side I started with renewed confidence. The first plug took a lot of effort to start moving but with some additional 'Kroil and back and forth on the wrench, out she came! Although softened by the 'Kroil, the deposits were significantly thicker with the entire length of the sleeve covered. The second plug too took a hefty effort to move and after some more 'Kroil and the 15-minute wait it came out as smooth as a babies bottom ...... trouble was, it left the sleeve behind still firmly attached to the head! At least all the ceramic came out with the main plug body!

Since by all visual observations, the sleeve in the head is only held by the carbon, I've stepped back to ponder my next move. I'm concerned that using the special removal tool will just dislodge it and it will drop into the combustion chamber and thus necessitate a head removal.

My other thoughts are that the "Kroil does work really well IF you can get the first 1/8 to 1/4 turn. Its clear in my mind that in my case, the sleeve separated as soon as the plug started to turn and so my cause was lost immediately.

That the "creaking" when removing the plugs is indicative of the carbon being present. New one in didn't "creak" and with no sleeve to turn, the last plug came out very smooth.

I took two of my old plugs, gripped the sleeve and tried to separate the sleeve from the plug just to see how much effort was needed. In both cases the sleeves started to deform but DID NOT separate from the main body! (Go figure!)

My truck does mostly highway miles in legs of 50 to 100 miles at a time; it does very little in town or idling. I run what should be good gas (Exxon, mostly), I don't use fuel additives, it burns ni oil between oil changes at 5,000 mile intervals. The day prior to starting the work, I had done a 60 mile freeway run, so I believe the engine was as "clean" as could be expected.

The plugs at 82,000 miles were "tired" - the center electrode was a small, retracted pin head (compared to the new ones) and the "hoop" was eroded and pitted to about 50% its original thickness. My mileage had been dropping - performance seemed just fine - and that was my main reason to start the change. Once I get through this ordeal, I will look at changing the plugs at 50,000 intervals just based on wear factors.

I did talk to my local dealer to see if they had the extraction tool, and they said this happens about 1-in-3 of the F150's they've seen for plug changes. They advise the owners that this sleeve issue is a possibility and warn them upfront that significant, additional charges may apply! My gut feel is that this means there will be a heck of a lot of F150's whose plugs never get changed within the life of the engine!

On the good side, at least it was a warm sunny day here in SoCal!

 

Rob,

So how did you get the sleeve out? How many plugs did you break?

 

So am I paranoid in saying im changing my plugs at 25K miles?

 

Broke one of the eight. Sleeve is still in there. It being Sunday, there are not too many shops open so I'm ccontemplating options!

My biggest concern is that the 'Kroil will have softened the carbon enough that when I hit it with the tool (which has to form a thread in the sleeve, if I understand it correctly) the the sleeve will just drop into the cylinder and then its a head-off job.

As soon as I reach a remedy - good or bad - I will post again.

 

2006M50B:

This is my $0.02-worth - I would not think of changing the plugs before 50,000 miles.

I pulled the front two drivers side at 30,000 miles for a "look-see" and they were pretty clean and in "as-new" condition in the spark areas. (These two plugs were also no worse for carbon build up when I pulled them this time). When I puled the plugs at 82,000, the working areas had deteriorated significantly and in terms of wear, etc., I would look for 50,000 miles to be a good mileage to change plugs on the 5.4. I believe the carbon build up is such that it occurs quite quickly, and there is not much to loose or choose after about 10,000 miles.

The other caveat is that I wouldn't change them if I thought I might trade the truck prior to reaching 100,000 - it's not worth the risks or the hassles. I knew I would have the truck through at least 100,000 miles - I had been thinking of keeping it indefinitely into the 250,000 miles range, but this experience has put a new light onto doing that. I can't say that (visually) the new plugs look significantly different so I would expect the same issues the next time around too.

 

Im hoping that this is the last truck I buy for a long time-im knocking on wood though because I said that with my ranger and ended up rolling it and totaling it out after 3 yrs, hopefull to have this one much longer

 

Rob,

I don't believe the electrode shield can actually fall into the cylinder. The top part of the shield is wider and will not fit into the cylinder head. Take a look at this thread.

https://www.f150online.com/forums/sh...d.php?t=316344

 

Bubbajoe28:

You were dead on - the top flare was still on the shield so at least it couldn't fall into the cylinder. That said, the tool worked as advertised and I was able to remove the shield - just a tremendous amount of the carbon crap all over it, though, and I hate of thinking I may have to go through all this again in a couple of years!

Only run it about 10 miles but the idle is noticeably smoother so I'll see how the commute goes tomorrow and if the gas mileage picks up any.

Love the truck - hate the plugs!

 

Another post that shows there needs to be something designed that can decarbon the combustion chamber esp this area b/n the shield and head. This would allow the shield to spin during the initial free up instead of breaking off.

 

Finally!! A factually correct article for the masses that accurately describes the removal procedure. Of course, it basically duplicates the TSB Ford put out on the issue more than a year ago....

And yes, as you discovered, the seat on the ground electrode prevents it from falling into the combustion chamber.

I'd be surprised if anyone came up with a way to lube the plug bore carbon deposits from the inside... it'd be a tough thing to do.

Personally, I think a new spark plug design might be a better option. If you look at the way the OEM plugs are built, the ground electrode is simply crimped-onto the body of the plug below the threads. If there was a way to make the ground electrode and threaded body from one piece, that would make it far, far less likely to break upon removal. It won't stop the carbon build-up in the bore, but it should make the plug less prone to breaking. I know they experimented with some plugs that had the electrode laser-welded to the body instead of being crimped, but I don't know if they held up any better.

I think the best fix would be to drill the bores deeper so the threads are closer to the combustion chamber. It would require a different plug, and some modifications to the heads (heat flow in the area might be an issue too) and the silicone boot between the coil and plug would be longer, but it would eliminate that long bore that the ground electrode needs to sit in and, therefore, reduce the chances of carbon building up around it.

Just my million-dollar idea....

 

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I also had a problem with my2007 F150. It was missing when on a load. I changed the fuel filter and ran sea foam in the tank but still did not fix it. I decided to change the plugs till I found out all the issues with this. After finding the price to do it I decided to try it. I also bought the leslie 65600 toll. I bought the Autolite HT1 plugs and got a deal for $8 each. I found that patience and carbon remover lubricant is the key. I sprayed the plugs with seafoam carbon remover lubricant and let set overnite. The next day broke them loose about 1/4 turn and sprayed a little more in. Let set overnite and the next day removed the plugs just like a normal plug change. No issues and none broken. I also have a leslie toll that is unused and going back to Amazon. It did smoke a little on the startup but stopped in about 1 minute and truck runs great now. Just take your time and don't overuse the lube and I also heard that in the later model trucks the plug cavity is a bit larger and does not have the breaking issue. I found a you tube video made by autolite that was very helpful. I also use seafoam in all my lawn equipment gas and they all seem to run better. I swear by the product and will continue to use it.

 

I would change the oil, anything you use seeps down into the oil.

 

I did a LOT of research before changing the plugs on my 2006 F150 5.4 liter. Here is what I found out, tried and proved to be effective. First run some good cleaner through your gas (I used Lucas upper cylinder lube and injector cleaner for over 2000 miles. I also did this on my F250 work pickup that also has a 5.4 for about 1000 miles.). This helps break up carbon around the plugs. I had heard using a 3/8" impact was the best way to break the plugs free so I purchased one. It does take some work finding the right extensions but it did work well. On the F150 on the passenger side I removed the ECM from the firewall to make it easier to get to the back plugs. Long story short, I replaced plugs on both pickups without breaking ANY plugs. I would also recommend having a shop vac with an attachment small enough to fit into the plug chamber as blowing the dirt out isn't completely effective. I blew them out then vacuumed them before and after removing the plugs. By the way the F150 had 113000 on it and the F250 had 108000 on it when I changed the plugs and they were all original plugs. I would be more than happy to send pictures of the plugs. The F150 was the second one of the 2 and I changed them all in just a little over 2 hours.