Back when we replaced the radiator, I noticed a slight coolant loss, like a few ounces every few hundred miles. At first I thought it was just air being burped out, so I didn't think much of it. Then I stopped checking the coolant so often.
Even with a new double row radiator she always seem to run a little hotter than I thought she should... but I thought maybe that was just the auto causing it to be hotter.
Fast forward to a few weeks ago and I started noticing heavy gray smoke when cold and she smelled more rich than usual when cold. I had assumed there was a problem with the cold circuit on the carb and I was going to swap it out when I could, but since she ran fine when warmed up I thought nothing of it. Edit: Now that I think about it, I think there was a thin stream of white exhaust when she warmed up, too.
Then yesterday when we were going to the store she went from cold start to almost overheating in less than five minutes! At one point I thought I smelled a faint whiff of antifreeze, but I thought it was the car in front of me.
I pulled over and turned off the car before she hit the red. Overflow bottle was practically dry, upper radiator hose was hot, as was the temp sensors, but the radiator was cold, hmmm. So I popped the radiator cap (after putting a coat on it first). Ooops, bad idea. What was left of the coolant escaped in an awesome explosion of steam! Fortunately the coat trick saved my bacon from being burned.
Started the car back up, quickly verified the heater was blowing cold, and darted (slowly) across the street into a hotel (Safer), and the time was 5:50. Napa auto parts was a half mile away and closed in ten minutes! I am terribly out of shape but managed to run-jog-walk just in time to pick up a 50/50 bottle of coolant before they closed. Walked back to the car, and she took over 3/4 of a gallon of coolant, started back up, didn't overheat, and we drove her back home.
Oil still looks clean.
What confuses me is she ran fine for months then suddenly no coolant?
- Head gasket had a small leak, which suddenly turned into a large leak.
- New radiator has developed a leak
- Cracked head/block?
- Some other cooling system leak
- stuck thermostat?
This engine was supposedly rebuilt 20k miles before we bought it... so who knows if they did a proper job on the head gasket? The rest of the engine had been put together with goopy gasket sealant (I mean everything).
I'm going to take the spark plugs out, see if any have been steam cleaned, then do a compression test. At the same time I might try to pick up a pressure tester for the cooling system.