So here's the story. My car was running really cold on the interstate. In town it would warm up a bit, but as soon as air started going through the radiator it would go below the C on the temp gauge. I assumed my thermo was just sticking open so I got a new one. Before I made the change, (about a week ago) I opened the cap and looked at my old thermostat. It looked like a thermostat alright. The reason I bring this up is when I took it out this morning and replaced it with a shiney new one, the old thermo was in 5 pieces. It had broke and come completely apart in the housing. It wasn't like that before. Have any of you heard of this happening?

But yes, there is a point to this. My car (with the brand new thermostat) still runs Ice cold. It's like there isn't a thermostat in it at all. The fans on the radiator never even come on. I am going to put the new thermostat in boiling water to see if it opens and closes correctly. But if this isn't a thermo problem what could it be? I know there is a sensor on that housing that I could replace, but I guess the reason I'm asking is because my old thermostat came completely apart. I was wondering if anyone knew what would cause it to just break and fail.

Ok. Mod can lock.

I was pretty pissed off and I knew that the thermostat was working. Thought I would follow up and update for future searches. Before changing the sensor I checked the rest of my engines operating vitals. I knew it was getting to the proper temp and not overheating, and I had heat with my heater. It had to be a gauge problem. So, before going out and purchasing a new gauge sensor, clean the connection to the small sensor on the thermostat housing. I used a small wire brush. I also inspected the other connector that goes to the ECU sensor. Due to a dirty electrical connection my gauge wasn't reading. After the cleaning the gauge went right up to center operating temprature. All fixed.

I am still curious however what would cause a termostat to completely fail and come apart. Any ideas?

One thing about these cars...When you know something is wrong, and know how to fix it, you have to check all the simple things. The damn gremlins always have something else minor screwed up that keeps you from realizing your success. Always something simple I guess.