When draining coolant out of my 2000 buick century, I am only getting out about six quarts. My procedure is as follows: I remove the lower hose from the bottom od the radiator, remove the drain plug in the front of the block (between the oil filter and starter) and open both brass vents on the top of the block (thermostat cover and other side). I would expect to get close to 12 quarts.
Is there a drain plug on the back of the block. If so, Do I need to open it, and where is it?
Thanks,
Steve