Thread: did a coolant flush, the wrong way?

11 liters is for a completely empty system. Doing what you did will not get all of it out. And no, you should not run the engine with the drain open.

There is coolant in the heater core, around the engine, trans cooler lines and in some of the hoses. You could fill it, drive it and then after a few miles, drain it again in hopes of the new mixing with the old and then replaced again.