over the last week developed an exhaust leak on the pass side. Usually a good tighten will fix the problem. looked this morning and 2 of the 3 bolts that connect the manifold to the downpipe have sheared off. any good fix ideas other than a new manifold? i thought about drilling them out and using a bolt/nut/crush washer but concerned i'd be wasting my time. Any thoughts appreciated.

 

Are the studs sheared completely off at the manifold (I.e. no nubs left)? If not, you should be able to get them off with an extractor.

If completely sheared, you can drill them out and use bolts. I did this on one stud I had to drill out.

Also, Paul grant sells used ones for about $50 IIRC.

 

2/3 are sheared

 

The other option, if you have the kit, is to drill them out, tap a thread (special Helicoil sized tap) and fit a Helicoil. Usually easier in alloy though. Had to do this on my cylinder head after the iron manifold distorted and studs sheared taking it off.

Résultats Google Recherche d'images correspondant à http://www.chronos.ltd.uk/acatalog/THREAD1.jpg

 

The threaded holes are open at the back.

Method:- Apply a good quality freeing agent spray onto the threads. Now clamp each nub tightly in a vice.

Now CAREFULLY and SLOWLY move the manifold back and forth on the stud in most cases it will run free after about two or three reversals.

Applying some heat locally in the area often helps with some extra freeing agent spray like bead blaster.
T/V