Exh Manifold to exhaust pipe bolt snapped off, now what?

[golferdude]

I am rebuilding a motor in a 04 Camry with a 2.4/4-cyl engine. It had a blown head gasket so we pulled the motor out and rebuilt it and put the time-serts in all of the head bolt holes. The motor had 186,000 miles on it and his daughter is going off to college out of state next year so he wanted to rebuild it to make sure the motor would last another 5 years. I put the motor back in this weekend and was hooking up the exhaust pipe to the manifold this evening and snap, the bolt snapped off. It snapped off even with the exhaust pipe flange. I was using a torque wrench to make sure I didn't over tighten the nuts. So wondering what the best solution is now? Being it is on the exhaust manifold flange, it isn't very thick so I assume a heli-coil won't work on it?? Is an option to remove the broke off bolt and drill it out and re-tap it to the next largest size??

Any ideas?

Thanks

[71Corolla]

Is it doable to remove the exhaust manifold? It would make the repair much easier. If drilled carefully, you should be able to use use a tap of the same size. The key is to drill a hole slightly smaller than the bolt in the exact center of the broken bolt, then run the tap through. The tap will remove the remnants of the old bolt and the threads will be restored.

When drilling, start with a small bit (but not too small to prevent breakage) and drill carefully and accurately, this will held guide the larger bit. For this type of repair, a drill press makes the job much more accurate.