1984 Pontiac Fiero 4 cylinder with a broken head

Tiny
BUDDYCRAIGG
  • EXPERT
  • 1984 PONTIAC FIERO
Engine Mechanical problem
1984 Pontiac Fiero 4 cyl Two Wheel Drive Automatic

What I thought was going to be a quick head gasket change has suddenly turned south.
A head bolt broke off and has so much carbon built up around it that I cant get the head off.
I had the car lifted off of the ground by pulling up on the head with my engine hoist.

The bolt in question is the center bolt on the exhaust side of the head.
It is centered between a pair of siamesed exhaust ports, probably the spot where there has been the most thermal expansion anywhere on the head.
I suspect the repetitive expansion is what allowed the carbon to be so tightly compressed.

The head of the bolt and about 1/2inch of the shaft broke off before I had rotated it 1/4 turn.
This makes me feel the shaft of the bolt is froze in place, as I would have felt a flex or torquing of the shaft if the problem was just the treads in the block.

So I have about a 2 inch length of shaft. 10mm in diameter, in a 12mm hole. With carbon built up around it, packed very tight.

These bolts are metric grade 11.9 which is harder than SAE grade 8, so drilling will be difficult to say the least, not to mention trying to keep it centered and straight.

I feel that I will be able to remove the bolt easily, after the head is off.

Any suggestions of how I can pull the head off of the bolt?
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Thursday, April 16th, 2009 AT 8:24 PM

11 Replies

Tiny
BRIAN 1
  • EXPERT
Only thing I could suggest is maybe take a torch and heat around the head area of the bolt and burn the carbon off and expand the head just enough to walk the head off with a pry bar, and spray with water after heating to expand and contract the area breaking it loose, or take a punch and hammer and hit the top of the bolt and shock the threads?Maybe that will loosen it?
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Thursday, April 16th, 2009 AT 9:15 PM
Tiny
BUDDYCRAIGG
  • EXPERT
Hi Brian,
I've also had the car raised up with my engine hoist hooked to the head, while rapping on the shaft of the broken stud with my air chisel. Still no movement.

I currently have the hole filled with Hoppe's nitro number nine cleaner and will let it set. Hoping it will soften the carbon.
(Who knew I would break out my range bag while working on a car?)
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Thursday, April 16th, 2009 AT 10:23 PM
Tiny
JACK42
  • MEMBER
Try a top engine cleaner designed to break up carbon build-up. Will the head come up off the block at alll?
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Friday, April 17th, 2009 AT 7:32 AM
Tiny
BUDDYCRAIGG
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No the head is not moving at all.

I cant be sure if i'm fighting the adhesion of the head gasket while i'm trying to pull straight up, since i've never tried to pull a head that way except for some motorcycle heads with copper gaskets.
Or if i'm fighting the carbon around the shaft of the bolt.
Or both.
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Friday, April 17th, 2009 AT 9:33 AM
Tiny
BUDDYCRAIGG
  • EXPERT
Well you guys didn't give me a magic answer, so I want my money back

it's a joke guys,
i was hoping against hope that someone might have an easy way out for me.

Drilling has commenced.
You remember the movie Armageddon, where they have to drill 800 feet in really hard rock on the meteor?
Well that's what these 2 inches feel like.

And would someone change my title back to "Certified Something Something" so the people I respond to will know that they are talking to a tech.
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Friday, April 17th, 2009 AT 6:48 PM
Tiny
BUDDYCRAIGG
  • EXPERT
2 hours in and i've got 0.600" left to go.
My air drill doesn't have a big enough chuck, so i'm having to use my dewalt, and i've drained all 3 battery packs.

And i've got that nasty taste of iron in the back of my throat from breathing the carbon dust
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Friday, April 17th, 2009 AT 8:58 PM
Tiny
BUDDYCRAIGG
  • EXPERT
Oh my god.
My back is killing me.

The head is off.

I'll be back later with pics.
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Friday, April 17th, 2009 AT 10:24 PM
Tiny
BUDDYCRAIGG
  • EXPERT
Ok
it took 3.5 hours
and the meaty part of the palm of my left hand is pretty much one huge blister.
But.
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Friday, April 17th, 2009 AT 10:53 PM
Tiny
JACK42
  • MEMBER
Good job on that one bro, sometimes there is no easy way out. Lol
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Saturday, April 18th, 2009 AT 8:05 AM
Tiny
BRIAN 1
  • EXPERT
The most important thing is you removed the head, thats all that counts.I hate jobs like this and I hated working on fiero's, this is the reason why!
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Saturday, April 18th, 2009 AT 10:01 AM
Tiny
LEGITIMATE007
  • EXPERT
Awesome man, you've just inspired me to finish this damn van(303) everything is corroded on this broad, and I have a stud stuck in the rear head too. Damn
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Thursday, May 7th, 2009 AT 1:51 PM

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