Snapped bolt in Cylinder Head
Old Mopar Aficionado Extraordinaire
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From: North West Jorsey
Barngal - the one time (thank goodness only one time) this happened to me, it was a head bolt on a Chrysler 2.2L 4 banger. I pulled the head off, used a Dremel tool and a grinder to flatten the top of the bolt. Then used a punch to put a small dimple in the middle of what was left of the bolt/stud. Started out with my smallest drill and slowly and carefully drilled out the center of the bolt. When I say slow I mean very slowly and carefully. Gradually increased bit size until I could get an EZ-Out in there. Luckily, with no tenstion on the head bolt, the EZ-Out worked very well. Honestly it was almost a full day job but it worked and not head damage ensued.
Very good. But try to find a left handed drill. They make them for this application. Try Sears or a good industrial tool supply. Home Cheapo may have them in a set. The drills are harder than normal too
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Joined: Mar 2007
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From: Sacramento
Got 'er done!
Thanks for all the advice here.
re: trying to drill into the broken bolt, which was on an angle...
The dremel worked for me--that was the trick! ground that bolt down to level, then even concave so it was easy to center a drill bit. Unfortunately, drilling into it didn't remove the bolt, nor did a left hand bit.
So I used the helicoil.
Because I was so nervous about it, I made it as hard as possible--I didn't drill the old bolt down far enough, so when I was using the tap, it wouldn't go in straight.
I used a tap when I installed my pyrometer, and I knew it shouldn't be that hard!
Once I stepped back, thought about it, I felt pretty stoooopid...
after I drilled the rest of the old bolt out, of course it tapped in perfectly,
the helicoil went in perfectly and the valve cover is on, and no leaks.
My little MINI engine looks awesome all cleaned up.
Thank you guys sooo much for talking me thru this stuff....
Between the valve cover, the rear brakes and an oil change I saved over $800 in labor...no kidding.
I'd rather sweat and learn something (as long as it finally comes out right)
Really, you folks here are the best!
re: trying to drill into the broken bolt, which was on an angle...
The dremel worked for me--that was the trick! ground that bolt down to level, then even concave so it was easy to center a drill bit. Unfortunately, drilling into it didn't remove the bolt, nor did a left hand bit.
So I used the helicoil.
Because I was so nervous about it, I made it as hard as possible--I didn't drill the old bolt down far enough, so when I was using the tap, it wouldn't go in straight.
I used a tap when I installed my pyrometer, and I knew it shouldn't be that hard!
Once I stepped back, thought about it, I felt pretty stoooopid...
after I drilled the rest of the old bolt out, of course it tapped in perfectly,
the helicoil went in perfectly and the valve cover is on, and no leaks.
My little MINI engine looks awesome all cleaned up.
Thank you guys sooo much for talking me thru this stuff....
Between the valve cover, the rear brakes and an oil change I saved over $800 in labor...no kidding.
I'd rather sweat and learn something (as long as it finally comes out right)
Really, you folks here are the best!
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Joined: Nov 2003
Posts: 3,654
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....now wait a month and post the same issue, only say a dealer did it. You'll get everything from "they have to give you a new head", to "they need to give you a new car"! FWIW, if the valve cover needs to come off often (not sure of the app) you may consider putting studs in. I had to do that with my race engine as the bolt holes were getting sloppy in the aluminum.
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Joined: Nov 2002
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From: lyman, utah
"on the LAST bolt, it snapped before it even felt as snug as the others. I had put antiseize on."
there is the problem.... never torque to specs when threads are lubricated unless the specs say so.......all torque specs i have seen are for dry threads..........that probably is the reason the bolt broke, over torqued.......very easy to do with small bolts
there is the problem.... never torque to specs when threads are lubricated unless the specs say so.......all torque specs i have seen are for dry threads..........that probably is the reason the bolt broke, over torqued.......very easy to do with small bolts
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cLAYH
3rd Gen Engine and Drivetrain -> 2003-2007
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Oct 11, 2008 11:07 PM