Although temps read normal, is the temp reading gauge really valuable at this point or are there damaging locallized hot spots caused by the leak?

I have a very small (comparitively) breach. I see small (1/8 inch and smaller) bubbles rise in the filler neck. I hear the sound of churning water from the heater core area (maybe from bubbles in the system).

I attempted to do a block integrity test with the kit from NAPA, but the coolant gets pushed into the test fluid no matter how much a lower the coolant level. Though technically contaminated, the test fluid turned from blue to yellow as hydrocarbons would cause.

I've had a couple of starts that took a little longer than usual, along with some sputtering as if it were runing on one rotor. During those starts there was a brief plume of sweet smelling steam from the exhaust.
Exhibit A:
http://theclient.hypermart.net/car/cough.mp4

I know folks run cars in this condition. Obviously a catastrauphic overheat condition would be the end. But my question is, am I causing further damage to the motor by running it in this condition until the rebuild?

 

Mathew,
If you want to keep this engine then stop driving it and rebuild it. Yes you're causing damage

No need for further testing this engine is toast

Good luck,
Fritz

 

Okay brother.