Hello,

Recently some troubling signs have begun to emerge in my heating/cooling system and I'm wondering where to start diagnosing this problem. In short... I took a long highway drive recently and, as usual, my heat-guage on the dash climbed way past the high end of the scale. As it seems to do this even in around-town driving, and that it was kind of roughly calibrated to begin with, I didn't think it was too abnormal and just kept on, because it seemed like everything was running fine. The next day however, when I went to drive it, I noticed the temp gauge is now broken, or popped, what-have you. It no longer registers at all -- dead. Concurrent with this, my interior heat has grown quite weak as compared to before. It would take a little while for the engine to reach full temp on the guage, and for me to put the choke all the way in, but once I had and kicked up the heat, it would be really nice.

Also, somewhat before this on a few occasions I noticed that steam was escaping from under the hood. When I popped it, just a little was leaking out of that top big tube connecting the front of the engine to the top of the radiator. It looks like this tube is due for a change, but that it's still workable for the most part, there are just a few little cracks, and how knows how old it is anyway... probably the original one from the 60's?! I noticed today also that a little steam/liquid is now escaping from the escape tube on the radiotor that runs down one side and out the bottom area of the radiator (on the right-side if facing the engine bay). While I was in there today after a short drive, I felt the heater tubing runing into the firewall and both tubes seemed to be feeling hot. I did not however feel the actual heater body unit.

So... my wording of this whole thing is probably not the best, because I'm rather tired today, but I'm hoping this might ring the bells with one of yous out there? I'm thinking about maybe replacing my in-line thermostat unit, as I've never taken the original out since buying the car to check it. I have a suspicion it might be failing perhaps? Are these expensive, and will I have to drain the block of fluid before I can take the tubing/part off to get at and replace this item?

Thanks for your suggestions, any and all.