Same here. Turn on the heater to floor/high. Fill the radiator to about 3/4 full. Start the car and let it get up to temp. Watch the coolant level. When the thermostat opens, you'll see the coolant get sucked into the block and the coolant level drop rapidly. Fill the radiator to the top and cap it off.I've always just let the motor run without the cap on until the thermostat opens and you see water flowing. Replace cap. Finished.