Seems I'm short a car atm, till I think think of something here. Funny how I was wondering where to replace the T-stat and this happens. I was rev'ing the engine after doing some work on the DIC & Compass when I see tons of steam coming out of the hood. I open it up and find this to my horror.



Seems the bolt holding the T-stat cover broke and half is still stuck in the head. :( No idea how this happened, unless whoever had the car last cracked it or something. If there is any good news, I found out my old t-stat was broken and I replaced it..but how to fix this bolt?

Drill/easy out, or slot with dremel and use a screwdriver.

That'* what I was thinking would have to be done. Now what if the thread is screwed? Is it soft enough to re-thread if needed?

I think it might be possible to fit a stainless bolt through the hole(or some other type of bolt that won't rust), place the thermo housing down and use a washer and nut to tighten it down in place. A dab of loctite might also be used.

If you can get the remnant of the bolt out, chase the threads and use never-seize not locktite on the new bolt. If you must drill, helicoils are available. Keep two things in mind:
1) Preparation is *everything*. For the O'ring to seal properly the manifold surfaces need to be very clean and free from deposits.
2) The O'ring does the sealing on a "C" engine, the bolt just needs to be tight enough to hold it in place. ( not even as tight as a spark plug).

WHOA! Don't do anything until you try it with a mig welder and a washer, (or a nut).
Wait until it cools to remove. Or use a torch and heat the area arounds the bolt. (don't burn the metal!)

It looks like its sticking out far enough to do that. After you are done, take the old stub and go to a parts store, anf get a new bolt.