Originally Posted by maxcichon
As soon as you turn the ignition to "Off", the heater solenoids will close and isolate that volume from the outside world. You may have flushed the heater core using this procedure, but draining it while "Off" may be problematic.
Yes, you are correct, but given what I have read in the srt6 service manual and elsewhere, it appears that this has been taken into consideration. More specifically, it states that after an hour or two of driving, the cooling system is designed to eliminate any trapped air in the system, such as that which may happen in the heater core.
best regards -- bob