Well, it happened. I used some PB Blaster on the stubborn #3 spark plug. I sprayed it good and let it soak for a couple of days. I went out Saturday to try and remove it. I got a couple of small turns out of it and then it snapped off flush. So, I guess my question is, what now? I obviously can't drive it down to an auto shop. Has this happened to anyone else? Short of removing the head, how would / did you remove what was left of the spark plug? Here are some pictures to better illustrate my problem. I did not blow out the spark plug well yet, that is why picture #2 looks worse than what it actually does. That is just a piece of porcelin from the other part of the spark plug laying there.
Thanks,
Jim

There is some good info within the space-wasting content of this thread. The final (follow-up) post is particularly useful. *warning* Its the PBB, so you can expect cussing:

http://www.pirate4x4.com/forum/showthread.php?t=635649&highlight=spark+plug

Well, I think you are relatively screwed on this one. Sorry, but it just is the way it is. <img src="/forums/images/graemlins/smile.gif" alt="" />

The Al threads should have pulled a long time before that plug snapped. So...you either have a tremendous amount of galvanic corrosion between the head and the plug, or it is really really cross-threaded. The other option is that the threads have pulled and it is now wedged in there nice and tight.

In the end, you are probably going to have to pull the head. Sean's suggestion of penetrating oil, heat and an easy out is good, but you are going to knock the electrode and the remaining porcelain into the cylinder and I think that plug is going to need more than heat and some massaging to come out.

The dude on Pirate had a few things going for him: 1) The engine blew all of the porcelain out. 2) He probably had iron heads.

With the head off, you can take it to a machine shop and have them fix it correctly. I am going to bet that you will need a heli-coil. You'll also have the chance to inspect the other spark plug holes and see if they need attention too.

I might point EB to this one via OT (he doesn't accept PM). For the readers, EB (aka engnbldr) is a retired machinist. <img src="/forums/images/graemlins/cheers.gif" alt="" />

I'm no EB, but having dealt with this type of situation in my Yamaha OB motor that was used in Salt water before I got it, I understand the picture.

If you broke the plug off, there is probably some type of corrosion involved between the dissimilar metals and gunk has got the threads all locked up. The solution that an old hand used to overcome situations like this was to tack weld a bolt head to the remaining material to be removed and then use A LOT of heat from a Oxy-Acetylene torch to heat the Aluminum while twisting on the bolt head with the proper wrench.

I, myself, didn't bother to do this repair as the casing bolt that snapped off wasn't imperative to the integrity of the casing. Additionally, I had snapped off a hardened easy out and couldn't remove it, so the reward wouldn't outweigh the work/price of the repair <img src="/forums/images/graemlins/shame.gif" alt="" /> <img src="/forums/images/graemlins/rolleyes.gif" alt="" />.

I don't know how much of my rambling will be helpful, but please don't be too aggressive with that easy out because it WILL make your life more complicated if you break it like me. Good luck!

>>>*Morning!

Margie had me wander over here, I will try to help.

With the common use of aluminum heads we now see sparkplug hang up as an almost weekly concern around the shop.

If the plug snapped at the base of the threads, then there are just two options. Since it should not hurt anything to drive it a short distance, (it will just miss) then taking it to a local shop is one option. They might attempt a removal by drilling it out, or they may choose to remove the head.

It all depends on access. Drilling one out while the head is on the car requires skill, I would take the head off myself.

If you decide to try to DIY, start with a small drill, about 11/32nds or so, even larger and be SURE of being on center and aligned. Then step out in drill size one step at a time. If a reverse drill set is handy, use them, often when you get close to the threads they will release and come right out. So we can see that drilling inwards can result in the piece of spark plug inside the cylinder and you are outside.

NEVER use an EZ-out on a stuck or jammed thread of any kind. Those are brittle, if they snap it's torch time.

The rule of thumb is this: If you can get the piece out with an EZ-out, you don't need one. Simply drill a pilot hole, select a suitable screwdriver, tap it in and remove the broken piece if the piece is sitting there loose.

If it's not loose, the EZ out will not work.

Now for you folks that will run into this problem in the future. When installing spark plugs, always use some thread lube like Never-Sieze or any high heat resistant lube.

Note motor oil usually can't handle the heat, although synthetic can. Ordinary oil can actually burn on the threads and create this problem.

Tip: When you DO run into the spark plug that refuses to come out, try this. Rotate it out until it stops. Then spray some penetrant, and tighten it back up. Repeat the process, you will notice that each time you will gain slightly until finally the plug will come. (Usually)..

Pulling harder once it comes to a stop doesn't work often, but working it in and out gradually clears the threads until out the plug comes.

From your description, I would say pull the cylinder head and take it to a good machine shop. Sometimes what seems to be the most work turns out to be the least...Good luck!....*EB

With the head off, you can try to cut the lip off that retains the electrode (taking care near the combustion chamber). I did this with an old plug to make a compression tester adapter using a hacksaw. A Dremel with a cutoff wheel might be easier in close quarters. The electrode should drop right out, hopefully this would give you something to grip on the inside diameter, perhaps with a fluted easy-out (what a misnomer that is!)??

Yeah, the lower unit housing on an OB motor isn't as precise as a cylinder head <img src="/forums/images/graemlins/notooth.gif" alt="" />. High heat and warpage go hand in hand, so...

Hey, I never claimed my heavy handed tactics were the most reasonable out there... <img src="/forums/images/graemlins/smile.gif" alt="" />

I hope you get it figured out! <img src="/forums/images/graemlins/cheers.gif" alt="" />

I have been giving this some more thought. Since the spark plug broke off flush, and of course, broke off the porcelin as well, I'm thinking the only thing holding the rest of the porcelin in is the electrode. So here is what I have been thinking - spray some PB Blaster on the porcelin, let it soak in for a bit, apply some heat and then crank the motor and let the cylinder compression try and force the porcelin out, kind of like a cork. This would only leave the remaining threaded part easier to use an easy out on, plus no drilling. Think this is a good idea? It really can't cause any more damage, and the worse that could happen is that it won't work.
Comments and or suggestions?
Jim

I have an update to my broken off spark plug. I was successful in my perserance to remove this. The compression from the #3 cylinder was enough to blow out the remaining spark plug porcelin. After that, it took some more PB Blaster, I soaked it down good, a touch of the heat, a 18" 1/2" drive breaker bar with complementary cheater pipe. And then it broke my first 3/8" socket I put on the easy out. When that socket broke, I thought for sure I busted off that easy out. Anyway, the Isuzu Gods must have been smiling because I got that piece out without messing up the threads! All it took after I got it out was to run a thread chaser to clean up the threads. The new spark plug (with anti seize) screwed in perfect.







Now that I got this little problem taken care of, how do I get the motor to idle down? It wants to idle at around 12 to 1500 rpm or so, it did this before the spark plug incident. What should I look for? Is there a idle adjustment somewhere?
Thanks,
Jim