Since you can only drain half of the coolant out, if you really want to replace all of your coolant it gets pretty involved.
I've read through different instructions, including the service manual, on how to flush and nobody seems concerned about room temperature coolant hitting a hot block. People used to worry about warping heads, why don't people worry about this any more?
If you worry about room temperature coolant hitting the block it seems like the best way to flush and fill would be to:
Start the car and let it come up to temperature;
Open the surge tank cap to relieve the pressure;
Being very careful not to self inflict with third degree burns open the drain cock and start draining the coolant (while it's hot and running, yikes!);
Add coolant continuously with a hose or a whole bunch of bottles until the coolant coming out of the drain cock is clear;
Stop the engine. Let the engine drain and cool;
Add 3 bottles of distilled water and let drain;
Close the drain cock;
Add 6.5 quarts of Dexcool;
Top with distilled water (which shouldn't be much).
How does this sound?
One more detail, the shop manual says to use "clean, drinkable water". If this is what the shop manual says, should I really use distilled water?
paul