T-stat housing ... stuck ... ugh
 

... all my wrenching is going wrong this week.:( I had to put my coolant flush on pause because of weather, and resumed today ... well, the t-stat housing will not budge. I swear I've got all the bolts out. Is this a common issue? Or am I just totally missing something here? How can I loosen it so I can remove the t-stat for flushing purposes? I don't want to damage the housing.
Maybe it's me, but it seems like there's just always something. Such is life, eh?
Edit to add: This is the 240D. Details, details ...

If all the screws are removed, just hit it with a rubber mallet. It's stuck to the gasket face.

Thanks BC. I always hesitate to hit things with a rubber mallet until someone here gives me the go-ahead.:o

Agreed with Brian...but do it verrrrry carefully. Especially if the wrong coolant had ever been used, the walls of the housing can be pretty thin and fragile.

This is very true, one one of my 240D cars, whunter had to help me find a replacement thermostat nhousing.

Maybe there's a market for these things as new parts, they seem to dissolve pretty often

Well ... the housing is off ... but now the t-stat itself won't come out. Either the gasket has disintegrated, or the PO put some kind of liquid gasket in there. It's got black crud around the sides and it's fixed itself in there good. Thoughts?
This poor car.

Chances are the black rubber seal is stuck to the alloy.I have carefully tapped around the thermo with a screw driver to break it away. It sounds like that seal is bad as you describe it as crud. If you prize the thermo out you may need to do some handy work with some RTV or see if you can get a new seal.