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  #1  
Old 08-21-2001, 07:34 PM
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Broken spark plug

I've gone and done it again

I was changing the plugs in a 500SEL and broke one off. This is the rear most plug on the drivers side so it's not the worst to get at its damn close.

I put platinum plugs in the car just over a 100,000 miles ago so as you can imagine they are welded in place. I sweated and cursed my way through 7 of them and have a blister on my hand to prove it

The last one went and broke on me so thats where I am now!

I've punched out the center so I have a nice round hole in the center but the only easy outs I could find are the ones that "twist" in and they seem to be causing pressure on the sides so no matter what I do I can't seem to get it out.

I've broken two sockets, the ones I put on the easy out and a 3/8's extension, to no avail!

Does anyone know of a "trick" or something that might help me out, I hate to think a "20 min. job" of changing the plugs could turn into the nightmare it has!!

Please help!!
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  #2  
Old 08-21-2001, 08:15 PM
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I hate to be the bearer of bad news but getting the remainder of the plug out may only be the small part of your problem. You, more than likely, will need to get the debris out of the cylinder. It could damage the top of the piston and/or the valves.

For sure you could get the broken plug out by removing the head and taking it to a machine shop and unless you can get a 1/2" drive socket on it I think that will end up being the way you resolve the problem. Sorry to sound bad about it but that is the way this diyer sees it. Maybe some techs have been here before and have a better answer.

For what it is worth, always use a little never seize on the spark plug threads and use a torque wrench to torque them to the specified setting.
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  #3  
Old 08-21-2001, 08:38 PM
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You could try this, but I am not a tech or a pro, its juist my thoughts.

Liquid wrench or wd-40 let it sit on it for a while, then attack it again.

If all else fails, remember to oil the threads or use some anti seize on the threads next time.

Alon
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  #4  
Old 08-21-2001, 08:44 PM
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Last time I had this happen (stuck plug that is, compliments of the Toyota dealer), it took a 1/2 drive deepwell socket and a long breaker bar. Took over an hour of steady pulling to get the plug out 1/8 of a turn at a time. Rachets mave give and not allow the transfer of energy. When the plug came out, it brought the threads with it (aluminum head).

This was on the wife's ride, and she last had the plugs changed at the dealer. Consensus is the plug was cross threaded.

Best of luck to you.
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'73 280SEL 4.5 (9/72)- RIP
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  #5  
Old 08-21-2001, 08:45 PM
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I'm no mechanic, but I think that engatwork is right. The debris in the cylinder could really do some serious damage. Unless there is some method that I don't know about, the head will have to come off so that the cylinder can be cleared out. Please don't attempt to start your car, even to drive to the shop. It wouldn't take much to damage the cylinder wall.
Good luck with that mess.
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  #6  
Old 08-21-2001, 09:39 PM
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Frankly, the least of my worries are what might be left in the combustion chamber once i'm done. What a magnet and a vacume won't take care of, turning the engine over before I start it will.

Oh, and thank your advice on the neversieze...if I had actually thought these plugs would have been in there for a 100,000 miles it would have made sense.

The next time I see someone actually torque spark plugs will most likely be the last, whoever does that???

Spank me later, for now I need a fix, not a list of what not to do!!

OK, I'm in a bad mood, you can spank me for that later to
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  #7  
Old 08-21-2001, 10:39 PM
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Try the breaker bar and deepwell socket, use an additional cheater bar if necessary. Take it slow and easy, maybe you'll get lucky and leave the threads in the head. Soaking it overnight with penetrating oil can't hurt either.

And yes you should torque the sparkplugs, just not to 100 ft pounds. Torque should be between 15-20 ft pounds depending on your engine.
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'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.
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  #8  
Old 08-21-2001, 10:43 PM
someguyfromMaryland
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Dear Mr. Toxicant,

I'm sure you're not in the best of moods with a broken plug and the threat of pulling the head on your 500SEL, but the others are right in advising to use anti-seize next time. This is also why I wouldn't let any plug sit in an engine longer than 30 k miles, I don't care if it was made out of Kryptonite!

I had the tightest plug I've ever seen in my Volvo Turbo this past winter. The PO had overtorqued the plugs and I paid for it. I got three out of four out on the first try, but number three was tight enough where I couldn't get any movement after about one flat and mor than 100 ft-lbs. I started the long process of applying PB Blaster every couple of nights after I got home. After several soaks, it still wouldn't budge. I finally got lucky on my last ditch effort before taking it to a shop to pull the head. I soaked the plug hole again with PB Blaster then fired up the motor (which I realize isn't an option for you right now), and let it run until my hand didn't want to stay on the exhaust manifold. Then I was able to get the plug out by going two flats out, one flat in, more soak, two flats out, one flat in, more soak, etc...

The moral of the story was patience and running the plug in a little each time it moved a little bit more for me. This kept the threads wet, I think. You can't run the engine, but you can probably figure out a way to get a little heat on the head.

Good luck, let us know how you do.
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  #9  
Old 08-21-2001, 11:48 PM
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Heat on the head! Great idea. Get a heat gun and heat that sucker up! (I thought maybe a blow torch, but then again, not a good idea) Then let it cool for an hour and heat it up again. Keep trying that. Also, WD40 is a penetrant. Let that do it's magic. Some patience and some heavy duty tools should do the trick. I also like your idea of using a magnet to pull the debris out of the chamber. Good luck with that project also.
Remember, we're trying to help.
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  #10  
Old 08-22-2001, 12:11 AM
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How to remove plug....

Hi there,
You are in trouble, and you will most likely have to remove the head to fix it. The way to remove it is to insert a bolt slightly smaller in diameter than the hole and carefully mig weld it to the broken plug. The plug housing will shrink as it cools and you can easily remove it by using a wrench on the bolt. As I said, this will require removal of the head, but I have used this trick on both sparking plugs and broken studs, and it does work very well. On a broken stud you usually have to just build up the end of the stud about 1/4" with weld before you can attach anything to it.
Good luck!
Richard Wooldridge
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  #11  
Old 08-22-2001, 11:16 AM
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YEsssssssss,

I got it out!!! Took a hacksaw blade and ground it down so it fit in the whole then sloted the plug top and bottom.

Then took an easy out, not the sprial one and drove that into the slots I cut and worked it back and forth.

I didn't even damage the threads...

I'm very happy at the moment

Thanks for the help!

ps,I think all the time I've sayed not having to take the head off I"m going to take my 6.3 out and blow the snot out of it, nothing like second and third gear rubber!!
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  #12  
Old 08-23-2001, 12:22 AM
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Might I suggest that to deal with the trash left behind in the cylinder, that you drop by Home Depot, buy a few feet of clear flexible tubing (small enough to go into the spark plug hole).

Attach one end to you vacuum with tape, insert into the hole and then turn it around in the hole. The flexible tube has a natural bend to it.

Good luck and this reader has read this thread with great concern. Another fine reason to swap plugs every 30 and check gap every 15. Plus antiseeze of course.

GLAD IT WORKED OUT!!! You get the "Damn your lucky" award nomination this week.
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  #13  
Old 08-23-2001, 07:49 AM
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wow

persistance pays doesn't it.
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