OK...I have a 383 that has about 4,000 miles on it since I had it rebuilt. It has been losing coolant slowly...the low coolant light will come on about a month after I fill the overflow tank back up. I'm not running any antifreeze at this point (I will when it gets cold out though)...it's just water and two bottles of Water Wetter. I have refilled the overflow tank twice since the rebuild with just water, so I'm sure that it's mostly water in there with a tiny bit of Water Wetter.

The engine did overheat once since the rebuild due to the crappy fuse holder on my CSI pump melting. I shut it off about 5 seconds after I figured out that the temp gauge wasn't lying to me when it went off the charts. *Hopefully* (crossing fingers) it's not a head gasket, but I don't think it could have blown or warped that quickly. I haven't seen any coolant coming out of the tailpipe, or on the sides of the block, or leaking from anywhere, and the oil looks normal, so the coolant seems to be magically disappearing.

I'm thinking that since I don't have any antifreeze in there, the water is just boiling off after I park the car once it's good and hot. Does this sound like a possibility? If that's the case, I'm going to drain it this weekend and run a 50/50 antifreeze mix instead of just the water and the Water Wetter. If I'm totally off the wall with this guess, tell me and I'll go poking around for other possibilities.

Thanks!

 

That light comes on when level in the radiator gets low, not the overflow. Is the level in the radiator getting low too? I bet that its your low coolant sensor going bad, those little fawkers go out all the time and throw the light. $40 sensor, 5 min install.

Also water boils at 212*, and i know for a fact your car isnt getting that hot.

 

Well, every time I fill it up, the light goes out, so I would assume the sensor is working pretty well. Fill overflow tank = suck what's in the overflow into the radiator = full radiator again = light goes out. That light hasn't lied to me yet.

I'll pop the cap off the radiator tonight before I leave work and see where the level is sitting at before I fill it up again just for grins...I'm betting it's low though.

 

[indide joke] Mr. *** says you are a moron! [/inside joke]