[rfishing]

mtflight, Thanks for the advice. It is 94 Seville STS. I found some articles on here about AC operation and that helped clearify the vents thing. Heat appears to be operating as designed.

I emailed Rxauto tech support with this same message. Previously they told me to drive it hard. They already replied tonight. Said, but not that hard! They thought 5500 rpms was a bit much. Told me to just drive it normal for now. That the overflow tank may have been equalizing.

I still have my doubts about the cooling effects of just water as well. Perhaps if coolant were in there, perhaps it would not overflow? After all water boils at 204 up here, I have yet to find what a normal operating pressure would be inside norstar engine, so calculating exact boiling point is not possible. However, I did read about another engine says, normal is 7 PSI. If that held true with Norstar, then my boiling point would be 21 +204= 225. Provided it is boiling before pressure has chance to increase to 15psi relief pressure, that would explain why the temperature went up to 235 and I lost water out the overflow.

I probably should consider that this is not like having original equipment repair. I will repeat that mile up hill and see how it does with just normal speeds, and exceleration. After all, just to be able to drive the car at this point is a blessing. Id be willing to drive without AC off for mountain pass, signs say turn AC off anyway. If it passes the normal driving test, I will have no worries driving the car for local non-mountain trips as well.

To be continued: