I want to perform a complete coolant flush on my 08 Crown Victoria. I have some 50/50 coolant and I guess the remaining distilled water will over-dilute the antifreeze. Is there a way to drain most of the water out of the cooling system? Will removing thermostat and starting the engine help with draining?
Don't know of a way to get all the water out. Some engines have drain plugs in the back of the block. My Ford 4.6 does, but they are rusted and hard to get to.
As an alternative, since it is nearly impossible to get all the water out, it is a good idea to use straight coolant and add 60 - 70% coolant to the system after the water flush. This will mix with the water already in the block to give you roughly a 50/50 blend.
FordTechMakuloco discusses this in his video How To Perform A Coolant Flush On Your Ford Vehicle (around 8:41 mark).