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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: AMK1001 on March 13, 2011, 07:25:34 pm

Title: Spark plug broke off in head...
Post by: AMK1001 on March 13, 2011, 07:25:34 pm
I was attempting to change the plugs & wires on my truck today.

Two of the spark plugs broke off. The metal hex part sheared off and the threaded portion is still stuck in the head. On one of them the ceramic insulator part pulled out in tact, on the other, it broke off.

Any ideas on how to remove what's left of them, without pulling the head?

This is on my '81 K20 w/454 big block.

Thanks,
Aaron K
Title: Re: Spark plug broke off in head...
Post by: Psycho71 on March 13, 2011, 07:45:35 pm
Man, Sounds like a tough one there. If they were stuff enough that they broke off an eaze out probably ain't gonna work. And any drilling/cutting on them will result in shavings in the cylinders. Maybe someone else will chime in here with a trick. But if it were me, I'd probably be planning to pull the head off.
Title: Re: Spark plug broke off in head...
Post by: 4x4orbust on March 13, 2011, 08:50:49 pm
i had the same problem when i first got my truck.    it was a 355 with 5k miles but sat for 5 or 6 years, rusted plugs solid.   

anyway,  i used an ez out (the short stubby ones) and it worked on all of them. lots of pb blaster.  some heat might help.   one had some porcelain that stayed in the plug, and dropped into the cylinder.   ended up pulling the heads anyway to get it out.   might as well try an ez out first, but plan on pulling them.   
Title: Re: Spark plug broke off in head...
Post by: Blazin on March 13, 2011, 10:48:32 pm
Heat, and penetrating oil with an ez out. As far as the porcelain, I would run that cylinder up to the top, smash the rest of it out then get a vacuum tip that reduces down and suck the pieces out. You could drill them out and then install Heli coils. While you are drilling keep a magnet right against the bit. All the shavings will stick to the bit, Just pull it out and clean it off often.
Title: Re: Spark plug broke off in head...
Post by: 1980c10 on March 13, 2011, 11:14:56 pm
get a larger short and stubby ez out, this has worked for me, if you use a small one it could break off as well. I borrowed one from a local machine shop, these are the guys to talk to about this as they have done it many times before.
If you drill or tap for a helicoil use grease or vaseline on the flutes of the drill bit and also on the tap to catch the shavings.

maybe try a hose connected to a shop vac to remove the ceramic pieces.
Title: Re: Spark plug broke off in head...
Post by: AMK1001 on March 15, 2011, 01:16:22 am
Thanks for the info. I'm going to try spraying them w/PB Blaster every day, and then use the EZ-out this weekend.
Will try to super-glue a pen to the remains of the insulator in the one plug, and see if I can pull the porcelain out in-tact.

Will let you know how it goes.
Title: Re: Spark plug broke off in head...
Post by: PromiseKeeper on March 15, 2011, 07:00:35 am
i hope that its at least all in the same head.   :o  keep us posted

just curious...what made them so hard to get out? carbon build up on the threads?
Title: Re: Spark plug broke off in head...
Post by: 1980c10 on March 15, 2011, 06:03:42 pm
the bigger the ez out the better, i think a #5 at a minimum is what you'll want to use.
Title: Re: Spark plug broke off in head...
Post by: Blazin on March 15, 2011, 09:30:52 pm
I have gotton plow trucks in the past that have rusted so bad around the plugs that there is noting left of the hex, and the porcelain just blows out when it was running.
Title: Re: Spark plug broke off in head...
Post by: AMK1001 on March 16, 2011, 10:32:58 pm
Quote
just curious...what made them so hard to get out? carbon build up on the threads?

The plugs themselves were rusty. Probably hadn't been changed in a long time. Whomever put them in didn't use any anti-sieze.
Title: Re: Spark plug broke off in head...
Post by: AMK1001 on March 19, 2011, 05:42:35 pm
The bolt extractor got them out. My dad had some that were short & not as tapered, and had hex heads so you could turn with a socket.

I lucked out and found the piece of porcelain that I thought was still inside the one plug, lying on the ground under the truck. It must have fell out & I didn't notice it...