Need Advice on Removing Broken off Stud and Head

19Fordy

19Fordy

Well-known member
Here's the problem. Engine is fitted with aluminum heads using bolts. While trying to remove the last bolt the bolt head snapped off even with the head. Now there is no way to grip the head bolt and the head will still not budge as the bolt seems "frozen" to the aluminum head.

This is a pretty expensive engine and the heads are no longer being made so i don't want to do something stupid.

Any suggestions will be appreciated.

I was wondering if the removed head bolts were loosly installed and the engine started, would the compression cause the head to come loose of the broken off head bolt still holding the head?

Thank you. Jim
 

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Dang. I hate broken bolts/studs. Yes to your question. Drain the water and loosely put the bolts back in. It is an old trick.

Another idea - I made a head puller tool a few years ago from a piece of 3/8" flat stock that I drilled 4 9/16" holes to go above the plug holes in the heads. It sits on top of the studs and I took 4 old spark plugs and welded a piece of 1/2" all thread on them. I screw them into the spark plug holes, put the metal plate with the holes over the 4 all thread/spark plugs, put a washer and nut on each all thread and slowly turn each nut in sequence until the head begins to come lose. I can send pics if you want.

That is a beautiful motor by the way.
 
19Fordy said:
Here's the problem. Engine is fitted with aluminum heads using bolts. While trying to remove the last bolt the bolt head snapped off even with the head. Now there is no way to grip the head bolt and the head will still not budge as the bolt seems "frozen" to the aluminum head.

This is a pretty expensive engine and the heads are no longer being made so i don't want to do something stupid.

Any suggestions will be appreciated.

I was wondering if the removed head bolts were loosly installed and the engine started, would the compression cause the head to come loose of the broken off head bolt still holding the head?

Thank you. Jim
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Probably not. How good are you with a drill? I you can center punch it dead center and start drilling and stop and check every few second to make sure you're still centered. measure the thickness of the head so you know how deep to drill. If you can get it out 1/4" - 5/16" without breaking through and then using a welding torch with a small tip heat the inside of the hole enough to burn the corrosion out. Then let it cool and the bolt will contract a little and loosen in the hole. I know this sounds like a job for a machinist,
It depends on your skills.

Another option is to weld a washer and then a nut on to the broken bolt.
A little risky around aluminum, Again depends on your skills with a mig welder. This is a little iffy ,If it was tight enough to break the head off it will probably break the welds.

If you can make a lifting device out of an old spark plug and screw it in the nearest spark plug hole and put a couple of studs in the proper bolt holes and put some upward pressure on the head and then using a rivet gun with a flat ended punch on the broken bolt driving the bolt down. The impact may loosen the stuck bolt. Not too much pressure on aluminum threads.

These methods are all kind of risky. The easy way is take it and a pile of money to the machine shop and have them set it up in a mill and bore it out with an end mill.
Is the engine out of the car and which bolt is it?

Bill
 
I feel your pain. Way too nice a car/engine to have to do this to.


Which bolt is it? Near the edge or end, or between 2 cylinders?



I'd soak the bolt in the head with Kroil for at least 2 days, preferably 3. Then lower the piston in the nearest cylinder, feed a length of rubber cord or hose through the spark plug hole to fill the combustion chamber, then turn the crank to raise the piston and put upward pressure on the head. Continue to soak with Kroil and smack the head around a bit with a rawhide mallet until it comes loose. A length of nylon/Delrin/hard plastic and a steel hammer would be a substitute to reach into the engine compartment. Motorcycle bungees with an end cut off usually fit through an 18mm plug hole.
 
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Jim, I’ve thought about your problem a bit and I think the first thing I would reach for is penetrating oil. I would use it around the broken bolt, then I would center punch the bolt and tap lightly several times then repeat oil. The tapping should cause enough vibration along with oil to loosen the the corrosion. I sure hope this goes well for you. Good luck
 
No need to fool around with a spark plug to cobble up a threaded item to make a puller

There is a good selection of metric wheel studs available,get a couple and fab one up. Used in newer Gm Equinox.Once the head is off the rest should be much easier.A little heat and a candle quench should get that broken bolt out.Having the whole bolt sticking out is a benefit.The bolt may even come out easily.


R
 
Ronnie, Perhaps I'm missing something as I don't understand your reply. Can you please explain further. I am dealing with a head bolt not a wheel stud. Thanks.
 
19Forty
I didn't have a broken stud BUT I had a head that was a REAL SOB to get off, took me damn near a week to get it to move. MY success came when I would flood the stud hole with PB Blaster, WD40 et al and then after sitting for a couple three hours I'd take my air blow gun and try and seal the stud hole as best I could and blast air in the hole and REPEAT. Each time I did this the head seemed to move a little more each time. Hope this possibly helps. Once It started to wiggle a bit, you could see rusty fluid get squished out around the stud, I'd wipe it off and squirt more in the hole and blow more air around and down in the cracks. As I said, each time it moved more and more!!!!
 
rbone said:
Dang. I hate broken bolts/studs. Yes to your question. Drain the water and loosely put the bolts back in. It is an old trick.

Another idea - I made a head puller tool a few years ago from a piece of 3/8" flat stock that I drilled 4 9/16" holes to go above the plug holes in the heads. It sits on top of the studs and I took 4 old spark plugs and welded a piece of 1/2" all thread on them. I screw them into the spark plug holes, put the metal plate with the holes over the 4 all thread/spark plugs, put a washer and nut on each all thread and slowly turn each nut in sequence until the head begins to come lose. I can send pics if you want.

That is a beautiful motor by the way.
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Hi Jim:

I'm sorry to hear about this and hopefully we can help you.

I use to fool around with Alfa Romeo's and they are DOHC all aluminum engines. Removing the head (which is studded from the factory) can be a chore much like your situation.

The factory tool, which I have and would be happy to loan you, works actually as rbone describes.

It has two thick steel plates that sit on top of the head studs. Two long bolts are threaded into the the farther most spark plug holes.

You slowly turn the bolts and the head lifts off nice and easily.

Let me know if you'd like to borrow it or see some picts to get an idea of what I'm talking about.

I never stripped a spark plug hole using this tool and it removed even the most stubborn head quite easily.

In the mean time, I'd hit all holes with Aero Kroil or a 50/50 mix of ATF & acetone.
 
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Fordy, what Ronnie is saying is that some modern cars use a wheel stud that matches the plug thread. It is 14mm by 1.25mm. If you're making a head puller it would be better to start with a wheel stud of the correct thread type than a spark plug.
Mart.
 
19Fordy said:
Ronnie, Perhaps I'm missing something as I don't understand your reply. Can you please explain further. I am dealing with a head bolt not a wheel stud. Thanks.
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Believe he is referring to using a wheel stud with the same threads as the sparkplugs to fab up a head puller using the sparkplug holes in the head.

I would consider using one of the very thin walled hole saws to clean out the area between the stud and the head.
 
Were you removing the bolts with a wrench or impact? If you broke to bolt with a wrench then you may have luck with the welded washer and an impact wrench on low. My guess is you have galvanic action between the shank and the head. Some penetrating oil in there may help also. Ultimately you need to break that chemical weld. If the bolt were froze in the block it most likely would have sheared at the base.
 
Frank's point is an excellent one; the remains of the bolt are probably frozen to the head The cure is likely to be patient use of penetrating fluid and vibration as suggested by 19Fordy and Ken Hash. If that does not loosen the head in a week, try starting the motor with head bolts in loose by a turn or two.
 
If you remove all of the other bolts can you slightly move the head to pivot against the broken bolt to aid lubricant penetration. Or did the rebuilder pin the heads and block for location?
 
Terry said:
If you remove all of the other bolts can you slightly move the head to pivot against the broken bolt to aid lubricant penetration. Or did the rebuilder pin the heads and block for location?
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Great idea, ......just don't go too far. I'd limit rotation to barely perceptible. A dead blow hammer should do it.
 
THANK YOU all for all your suggestions. Was using an impact wrench and then switched to a breaker bar. BIG mistake as head of head bolt snapped off. I can't thank each of you individually but, I want you to know I really do appreciate your taking the time and straining your brains to help me.

Terry: I don't think the heads are pinned so your "pivoting" idea might work.

Tim: Thank you for your willingness to loan me your special tool. I will "save you" as a last resort.

Mr. Seery: If a thin walled hole saw was used to cut around the perimeter of the broken bolt, would it enlarge the stock head bolt hole making the head unusable or would a sleeve now be needed to fill in the enlarged hole?

Please keep posting ideas as they arise. JIM
 
I vote no to the hole saw idea. I have a pair of Offy heads here some forgotten clown tried to to hole saw some of the frozen fasteners ,now the heads are just wall art. They also tried to drill out the pistons , opps , thru the block ………Clowns
 
I was thinking of the slight pivotting method and was glad to see it mentioned above.
Would I be out of line suggesting the classic broken stud/bolt technique of welding?
Weld a washer to the bolt, building up the weld and then weld a nut to the washer.
The heat input might help break the corrosion bond. Copious amounts of your favourite penetrant applied beforehand over a period of time would almost certainly help too.
Mart.
 
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