I just got done changing out the thermostat in my '95 Geo Prizm. For the last couple of months I just figured it was being super efficient at keeping the engine cool, until a co-worker pointed out that it might be broken. Turns out it was!
Took about 4 or 5 hours, and that included replacement of the coolant, and an attempt at fixing some of my dashboard lights as well. Not sure if the lights took, but I'm going to leave them for another day. However I just took the car for a 10 mile drive, and it heated up perfectly, and I could even use the heater, which seeing as we're in the dead of winter is a good thing!
Tomorrow begins a new week. I haven't trained for 3 days now, so I'm feeling like the worlds biggest slacker. Hopefully I'll get on the bike trainer tomorrow morning, and can start racking up the miles!