I'd try a bolt extractor first. Sometimes they even work.
While we have this pic in front of us ... is the little wingnut on top of the cylinder in the center of the pic just to bleed the cooling system? ... if turned the wrong way, it'll sure lets a lot of coolant out in a short period with the engine running (... ask me how I discovered that)
.. is the little wingnut on top of the cylinder in the center of the pic just to bleed the cooling system?
Found a new water flange on line for $75 with shipping, but now have realized I can't get to the bolts to replace it without pulling the head of the engine (which it bolts to). Either that or pulling the entire front gear cover off.
Thanks for the pic. That is how I thought it was constructed so went ahead with the drill out plan. No problem drilling out the stud from the top until I could see I'd broken through to the bolt into the housing. But was still frozen in place so continued to pour Kroil into the openings and soaked the gasket from the sides. Then started tapping with a hammer to try to unfreeze it.
Unfortunately the corrosion was stronger than the water flange casting it was attached to which broke off. (Now I can at least get the top part back to my shop and cut and drill the thermostat housing off, but not exactly the way I wanted to do it). Probably should have put an Oxyacetylene flame on it for a bit but was worried about bursting the thermostat inside and having all the wax/oil run down into the engine.
Found a new water flange on line for $75 with shipping, but now have realized I can't get to the bolts to replace it without pulling the head of the engine (which it bolts to). Either that or pulling the entire front gear cover off.
Thought I could just pull the alternator & bracket and the fresh water pump off and would be right there. There is only about 1/16" clearance between the back of the water pump housing and the heads of bolts that have to come out. Then noticed that the back of the water pump is actually an integral part of the front gear cover. What a silly arrangement. I sometimes wonder if engineers stay up late at night thinking up things like this, and mounting oil filters on the sides of engines.
Regardless, a simple thermostat replacement has ballooned into a major project I really didn't need right now.
Kevin Wright
E35 Hydro Therapy
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I guess I’m a day late and a dollar short, but since the heads were off of the bolts, why didn’t you try to pry the cover up off of the flange by working a screwdriver tip in between them, then either twisting or prying the cover up? The old gasket and goop were probably holding it on at that point. The bolts might have been turned with vice grips if the cover had come off, I think. Sorry to be a Monday morning QB......