Re: How do you repair broken intake manifold bolt on Merc 496
 

Another idea, there are reverse drill bits, center punch the bolt or screw, rarely do you drill in much more then 3/8" in and it spins the fitting out.

Phil

Re: How do you repair broken intake manifold bolt on Merc 496
 

What size threads? Or the size of the socket used.
Center punch it, then drill the body out using the correct tap drill size. Then run a tap into the hole to dislodge the threads. Make sure you centerpunch it directly in the center, and drill straight as possible. Helps if you can get a file in to file the burr off to give you a flat spot.

A LH drill works great if it broke because of over torqueing. If it broke because it seized, then it may not back out.

Re: How do you repair broken intake manifold bolt on Merc 496
 

Either the threads seized or the bolt bottomed out do to insufficient hole depth. The bolt twisted off under torque.

Appreciate all the suggestions. Especially the warning about disconnecting the ECU etc. if welding. Never would have thought of that.

Bill