stuck thermostat?

Looks like I can rule out the thermostat



One interesting tidbit though, when I pried off the thermostat (after removing the upper radiator hose) I could hear it sucking in air, showing me there was a vacuum underneath the thermostat

Isn't there usually a bleed hole in those things ?


For now, I've installed the housing without a thermostat and after the silicone cures overnight

And then we'll see how it does

Any thoughts on that vacuum though?