4.6 thermostat housing problem

Has anyone ever tried to replace a thermostat on a 2000 4.6 Mercury Grand Marquis or Crown Victoria? I managed to get one long bolt out but the other one is really stuck hard and I am afraid it will snap
before it breaks loose.
It seems that the housing sits on top of a 3" plastic piece and shares the lower gasket with the intake manifold. If it breaks, the whole intake manifold has to be removed and a new manifold gasket has to be installed costing upward of $200 to $400.
Previously I had a 4.6 engine in a 92 Merc Grand Marquis and it was designed like every other engine using two short bolts holding the goose neck to the engine.
I get so damned sick of these design changes that make things so much more difficult and expensive to repair. If these damned engineers would adhere to the adage "If it ain't broke don't fix it" life would be a hell of a lot easier. Sorry for the venting
Wayne
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yourself(if you are at all handy mechanicly). These intakes are among the easiest to remove/install. I have changed probably about 10 or so intakes and t-stats on the 96-97 4.6Ls with the plastic intake and I have never broken a bolt. They do go into aluminum so they do get stuck. I think your chances are very slim that it will break. GL
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Thanks Scott:
exactly what is that black plastic piece under the thermostat goose neck? Does it enclose an aluminum part or is it part of the intake manifold?
Thanks again
Scott M wrote:

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plastic. Look at the rest of the manifold, is it black? tap it with your finger nail, does it sound like plastic? Im sure it is. Be very careful when installing the new t-stat, there is probably just an o-ring that you just squish a bit to seel it up. It doesnt need to be super tight. Is it overheating or leaking? If it is leaking you might have a crack in the manifold-very common.
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No it is not leaking. The temp sometimes does not come up on the heat guage as it should (often sits on zero or slightly above) and other times it will come up to a little less than halfway. Fluid is level is O.K and it is not air locked. The heater does heat alright though. The thermostat bolts have never been touched and are tight right from the factory. I am beginning to think I should just forget about it.
Thanks for the help
Wayne
Scott M wrote:

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================================Sounds like the t-stat is stuck open. It really should be fixed. Unless it is a gauge problem, the way it is now you are never getting up to proper operating temp.
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