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PoorManzImpreza

So..head bolt broke in block..

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Yes..so I get a nice 17mm inpact socket and go about getting the heads on my turbo engine (ea82T) off all bolts break loose, took a long breaker bar and some grunt, except one which snapped $%&!@#$:banghead: :banghead: :banghead:

 

So I continue on and remove the head.. Cause of frozen head bolt? Blown head gasket leaking coolant into cylinder bore and head bolt..add that to engine sitting in that state for who knows how long..end result rust!

So I'll have to drill the bolt out as it broke almost level with the block surface..

 

So should I drill and tap a 12mm??

 

Also both head gaskets were blown at exactly the same place on the gasket..I found this interesting..

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Good luck getting that hardend steel bolt out:banghead:

Your heads sound like they need to be resurfaced also.

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I would suggest talking to a machine shop before you get in too deep. Ask them how much to remove the bolt and repair the hole (probably core-drill the bolt out and TIG-repair and retap the hole).

 

Might not cost too much, compared to broken bits, easy-outs and frustration.

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you should at least try to file a flat surface on two side of the broken bolt and see if you can use a vise-grips or crescent wrench to take it out before you get too exotic.. just protect the block from getting any metal filings in it anywhere... it would probably help to heat the bolt up and let it cool before trying to remove it, too...

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what i have done in the past is drill the center of the bolt out and pound in a torx bit to act as an easy out and try and romove the bolt that way

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Hopefully your engine is out of the car ? I would try useing left hand drill bit. And if that does not work try a L.H. tap . And if that does not work a L.H. bolt. Also use heat around bolt hole with bees wax instead of penatrating oil . Use wax when bolt is hot . not red hot , but very warm. Also when you drill a hole in the broken head bolt it takes some of pressure off the threads making it easy to remove . Make sure to drill in the very center of broken bolt . One more tip, heat around the broken bolt hole and cool the broken bolt with a ice water stream from a squirt bottle All the tools can be found on a thing called the Internet. You may have heard of it.Good luck and take your time. Drill size 19/64"and tap size 3/8" L.H.

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yeah upon further looksie it looks like the bolt snapped off two threads in on the threaded section of the bolt which means that it snapped just below the block surface..typical really..I've access to a drill press and yes the engine is out of the car..I've drilled hard steel before by hand and by the drill press and if you use machine oil liberally you can drill it so it doesn't even dull the bit (it helps to use a really good bit designed for hard metals).

 

Any reason why I can't just make the jump to 12x1mm? 11x1mm Pitch is VERY hard to find where I live...

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Going up a size depends on how much clearance there is inside the block, around the threads - for oil passages, coolant passages, etc.. WJM might know this best?

 

 

Ziggy, can you elaborate on the beeswax technique?

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The first problem is getting the bolt out of the block. Good luck with the drilling. I recently drilled a broken exhaust stud out of a head and used a Heli-coil to fix it back up. For a head stud, you may want to talk to a machine shop and have them make you what's called a "step stud" (larger on one end).. You can tap the block to a larger diameter install the new stud. I've used a few of them before and they work well.

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You have to use the beeswax with heat,and it wicks into the threads (I have a beeswax candle) I heat and let it cool 2 to 3 times. Be careful with Aluimium as in not getting it to hot . Drilling with L.H. bits sometimes will remove the broken bolt if you use heat around the broken bolt hole and cool the broken bolt with ice water in a squirt bottle .Also with the left hand drill bit it is turning left the way you want the bolt to go to remove it.Heating around the bolt hole makes the hole larger when it's hot and cooling the bolt shrinks it causeing some movement between the bolt and bolt hole.Once it moves, it comes out no problem . Sometimes you have to use L.H. tap and L.H. bolt . Hopefully this makes sense

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