Broken spark plug

[tagham]

I recently had a very rare occurence (judged based on 0 postings on the topic). The spark plug in the #3 cylinder (driver's side, furthest forward) broke in half--while I was driving! I don't know how many miles the plugs have on them (I bought the car 25,000 miles ago)--but everyone says that, even if they are old they shouldn't break.

Anyway-my problem is: the porcelain and nut part blew out--the threads and electrode stayed in. Any suggestions on how to get that out?

I've attached a photo of the part that blew out.

Weird.

[abisel]

Well... hopefully what remains in the head didn't screw further into the head and drop down into the cylinder. Maybe it unscrewed itself a bit until you were able to shut down the engine.

In any event, you probably will have to drop the engine to get good access to the spark plug hole and then a pair of long-jawed needle nose pliers might get a good grip on the electrode enough for you to slowly back it out of the head. Good luck.

[echrisconnor]

Yup, to get that out of there you'll probably need to pull the engine. It may be possible to pull your exhaust and fish around through the exhaust valve, but that is unlikely to get all the pieces.

Beware, if you drove this for any period of time with significant chunks of debris in there, you may have done some piston/head/valve damage.

[ken_xman]

maybe change the cheapest part more often.
...you need to borrow $6 ?
Just busting your chops. Hope the motor is ok. I get the willies thinking of what that could do.

[Dan Owens]

I'm sure you already know this but I wouldn't drive it or start it until you get that out of there. Last thing you want is parts falling down into the cylinder tearing things up.

[Schrup]

I have to say that is about the ugliest pic I have ever seen posted on this board. I wish you luck on your engine drop & hope there isn't any damage. This may be a dumb idea, but has any one considered fabbing a nozzle to fit on the end of a good shop vac?

[tagham]

Thanks all for the comments. The moment the plug blew I did pull over and turn it off--haven't started it since. (Hopefully the quick response minimized the damage.)

I have dropped the engine already. I was trying to use a screw-type easy out, but got nervous because I couldn't see what I was screwing into. So I stopped--and came the board here to look for advice.

Trying to twist on the electrode is a good idea--I can't quite visually see if the electrode is still there or not. I will try that tonight.

If the electrode is gone (in the engine--big trouble---out of the engine--good) then--is there any advice for getting the threaded part out?

I thought some kind of device that would go down, then extend out and grab the threads would be good--sort of like a reverse claw--but I have no idea if I could get enough torque, let alone if such a tool exists.

And, finally, ken_xman--if you are offering donations--I will gladly accept!

[Schrup]

I would get some kind of penatrant in the threads like Aero Kroil or PB Blaster untill you come up with a plan to get it out.

[Porsche_monkey]

Why not try a vaccum on a small tube to try and pick it up?

How thick is the wall of the remaining thread and what is the ID?

Thread extractor? Or possibly a LH tap? If you're disassembling then take it to a machine shop.

[vash]

holy kamolee! that is hideous! did you take the valve cover off? that should give you a bit more room. where in the bay area are you located? my buddies miata beat itself to death when the electrode came off. i hope your quick shutdown saved the day. post a picture of the part stuck in the motor.

cliff

[yelcab1]

Looks like another Bay Area engine drop party.

1 saturday
2 dozen donuts
2 cases of beer
2 cases of soda
3 large pizzas
a dozen helpers
two borrowed jacks
2 heavy jack stands

And, that sucker will come right out.

[vash]

tagham, the best situation would be to live next door to yelcab, but i checked, the homes are not for sale damn!

but can you use a dremel to put a notch into one or two sides and make a big flathead screwdriver fitting out of it? then maybe you can slowly tap it loose. make sure more crap doesnt go in tho. let me know if you need help, i almost want to see this one go down.

cliff

[abisel]

If by chance the remaining piece in the head is loose, you may be able to work it out slowly using the c-ring pliers that expand outward when you close the handle. I still think a pair of really long nose needle pliers may do the trick, IF the plug remanents provide a good clamping surface. OR a long thin flat bladed screw driver may find a flat spot on the inside of the threads/insulator that will allow you to walk out the remanents.

[justesen]

I had this same thing happen on a 1991 SHO (sorry for the comparison). When I shined a flashlight into the spark plug hole, I noticed that the threaded piece that remained in the head was actually "broached" for an allen wrench. I doused it aerokroil, put in the allen wrench and backed it out. I then adapted a piece of thin walled hose to my shop vac and put it in the spark plug hole. I was lucky enough to get all the pieces out. I put a piece of bed sheet over the outlet tube in the vacuum so I could see exactly what I got out. I then did the "puzzle assembly" with all the little pieces to be sure everything was out.

I put in a new plug, fired her up and never had a problem. I was very lucky. Good luck

Jay
1977 911S

[911mot]

This may not help but....

Twice I've had sparkplug threads break during removal at the nut, just like yours, on the cast iron head 1.3 fiesta engine. This is due to corrosion siezing the threads .At first it looked like head off job but with after a bit of jiggling and tapping with a screwdriver in the ceramic I managed to grab expose the electrode enough to pull on it with a pair of pliers and it came straight out with no resistance complete with ceramic and tip. All that was left in the engine was the metal threads. I then hammered used what used to be a chisel in to the plug hole until it was tight and removed it with a pair of vice grips. I doubt that the last part would be easy or wise to do on your engine however if you can get the ceramic out you will be able tell if any chunks have fallen in.

http://www.ngkspark.com.au/spark_plug_analysis.htm

[tagham]

It's out!! Thanks for all of the advice.

Admittedly there may be a couple bits of ceramic left in there--I'm borrowing a boroscope tomorrow to look around in there to see if I can find the remaining bits.

So--here's how it came out. The engine was out (although I am not sure this would have been necessary in the end). I took the valve covers off--this helped a ton. I then was able to use the long needle nose pliers to grab a couple of these easy pieces laying near the top. The needle nose were too big to get down to the electrode. So, I attached the easy out I had to a long extension. Then, using a 10mm wrench was able to put enough torque on the extension to get a good bite on the threads and it popped right out.

Amazing. Glad it worked without too much drama. In the end, it was much easier than expected.

I've attached pics of the pieces--and the now legendary tool used.

[abisel]

WOOHOO!!

[yelcab1]

Shootz, there go the dozen donuts. Nice job though.

[john70t]

Allright! Perfect!
Now... what caused it, and how to prevent a repeat?

Generally, that would be caused by excessively high cylinder pressure- timing way off, carbon buildup, with low octane gas.

Mabye a German company who has a corner on the market and a namesake but still makes cheap overseas ..stuff.. to sell?

[TonyG]

tagham

I had the exact same thing happen to me (or rather my mechanic).

When I purchased my '82 911SC in march of this year, I took the car over to my mechanic to have the valves adjusted and the plugs changed.

My mechanic, while trying to remove the number 4 plug, had it break exactly like yours did.

He got the rest of the plug out w/o having to remove the engine to my amazement. I'm not sure what tool he used... but he got the sucker out. I saved it and have it in my garage somethere.

It was the same plug you removed also (brand of plug).

As a point of reference... my car was running perfectly with no detonation, perfect a/f ratio, etc... It looked to me like there was possibly some slight corrosion where it broke.

TonyG