What it was exactly: My wife has a 1985 Peugeot 505 turbo 2.2 liter four with 150,000 miles on it. I had gotten a thermostat a while ago and was looking for an excuse to put it in. She was complaining about not getting any heat out of it and mentioned the engine temperature wasnít warming up. I thought nowís my chance. It looked easy, right on top, in front, similar to my M103 that I had just changed, should have it done in an hour, NOT. I took the first of the two bolts off and it turned pretty hard but it did come off. I tried the second, harder to get to one and it seemed harder but it did turn a little. Itís been a long time since Iíve turned a rusty bolt and mistook the movement to the bolt turning when it was really just the head.
Afterward there was enough left to grab with vise-grips but it still didnít turn and I really couldnít get to all sides to really attack it. So much for my one hour job, now time to re-schedule a two car family as a one car family, feasible but not pleasant.
Plan B. The thermostat was mounted on this thing with lots of stuff on it and bolted to the head so off it came. I put in a vise and squared the bolt remains off with a dremmel. Broke that off too.
Plan C. I brought it into work and gave it to one of the rocket builder machinist motor heads. He ended up breaking off an ez out in it. The server wonít let me quote him directly, or me either.
Plan D. Schedule a bunch of time. I used a drill and a dremmel with a chainsaw sharpening bit got about 80% of the bolt (and old ez-out) out, and a propane torch and some wax for the threds. Tried another ez out. Broke that too.
Plan E. Being careful of the aluminum threads I used a variety of drill bits, dremmel stones, lights and magnifying lenses to take out as much as possible of the old bolt and dug out the remnants of the bolt, it looked more like a spring. It was still hard to get out.
Morals of the story:
When doing a one hour job, reserve the rest of your life just in case.
Another reason for keeping a proper mix of coolant (with corrosion inhibitors)
Results: The car still doesnít put out any heat.