Broken tap in engine block.

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I've just finished swearing... so I've now got to figure a way forwards.



Last job before the summer was to replace the thermostat. Simple job - 3 bolts. However, I removed one, but the other two snapped straight off. With a bit of persuasion one came out. However the lower one (as in picture) would not budge, even with WD40 overnight, heat etc.. So I've drilled it out. So far so good.

The threads for this hole were shot from drilling the nut out, so out comes the M6 tap. Again, with WD40, I tapped the hole, however on the last bit the tap breaks.

So, I've now unsuccessfully tried a tap extractor (3 pronged thing which just seems to bend) but am at a loss how to get this tap out (each idea I try the hole gets slightly wider ....) , and when it does come out, whether I tap a new M8 or use a stud secured with metal epoxy.

Suggestions?

Cheers, Richard.

[rtg]

Phillpot - how much for the inlet manifold?

I'm now resorting to the dreaded dremel, so any alternatives would be helpful.

Richard.

[rtg]

Thanks all for the help!

Stig - the ThreadDoctor looked promising, but his EDM machine is broken and will not be fixing it soon.

Phillpot - thanks - I'll take this inlet manifold off and see if I can free it on the bench. If not I'll give you a shout.

Everyone else - I'll be trying all ideas...

It's amazing how a 30 minute "I'll just remove these 3 bolts and pop in a new thermostat" turns into major exercise!

Cheers All!