Re: 1950 Packard 288 Auto overheating HELP

Posted by Fred Puhn On 2010/2/1 14:10:07

There may be a bit of confusion about what a thermostat does. A thermostat controls the minimum temperature of the coolant, not the maximum temperature. You will not prevent overheating by changing to a different thermostat temperature.
When I got my 1950 Packard last year I checked the thermostat and it was 180 degrees. I changed it to a 160 degree thermostat because I found that specified in a Packard book. If the coolant runs at a lower minimum temperature it will cost fuel economy and power because more energy is wasted to the coolant. However the lower mkinimum operating temperature requires more time to reach boiling if you run into a difficult operating condition such as extended idling or climbing a long steep hill.
I think the reason they used to recommend changing to a higher temperature thermostat in the winter was to make the heater work better. I cannot think of another good reason right now.
Modern cars use much higher coolant temperatures than old cars, which increases gas mileage, power, and reduces the required radiator size. However the system has to be sealed and pressurized to prevent coolant loss.