Tools & Fabrication - broken exhaust bolt on the head

drilled, tried to extract, extractor broke, leaving hardened metal in the head. now i cant drill that out. any advice?

Lil dremel with a tiny carbide bit to the material out or weld a nut on it if need be weld some bogger to it first to make a spot for the nut then weld the nut to that let it cool should pull right out... Speaking from experiance i do it all the time and have had to deal with other peoples bits/extractors in also. Its a aluminum head u dont have to worry about the weld sticking to it even cast irons forgiving. If it doesnt work first time try again itll def come out gd luck

You can do the above BUT if the weld doesn't work you just hardened the bolt more.

Your at the point that I just pull the head and drill it on on a drill press.

You can do the above BUT if the weld doesn't work you just hardened the bolt more.

I understand you are a moderator, but please don't give this advice again. Just heating a bolt will not harden it. There is more to it than that. At the very least you would need to heat it and then quench it in water to do any hardening. Then it is hard but very brittle.

OP the advice in the first post will work. Weld a nut the existing metal, then let it cool until it returns to normal color, and then try to back it out. I've done this many times and it works great.

Now taking the head off and drilling out the existing bolt with a drill press is a nice option. But not needed at this point.

i have a 94 3.4 with two broken exaust bolts that are broken off in the head on the driver side there is very limited working space what is the best way to drill these out without hitting a water jacket it is the front two bolts on the exhaust manifold top and bottom any advice