radiator question

[gerretw]

I have a 68 chevy c 20 longbed. It was sitting for a long time before I bought it. It has a305 out of a 73 buick in it. After much putzing around to get the temp gauge to work, I finally had one of the posters here mill down a sender to screw into the block. It started working and showed the temperature was out the top - I popped the radiator cap - red red coolant spilled out. I changed the t stat, and it seemed better but erratic. I had the block and radiator flushed, filled with green coolant and the needle stayed on the bottom left. So far so good.

Then, recently I was topping up the oil and I took a look in the radiator, and it was a gallon low. And red, not green. I added a gallon, and I kept driving it, then 3 days ago the gauge shot up to the right -- not in the red, a couple ticks below it. This morning I drove maybe 10 -15 blocks and it shot up again. I was thinking the radiator was plugged up again. That my driving it around for a few hundred miles loosened up a bunch of scale.

Does this make sense?

G