When filling the system - keep these general rules in mind:
Turn the heater on "full hot" -
The cooling system cap MUST remain "OFF" while filling, at no time should the system be subjected to pressure.
Don't let the car overheat.
Make sure the cooling fans are working.
Alternate the RPMs between 2500 and idle about every 30 seconds to force the air out of the system.
This process can take up to 20 min..
The heater should get hot. If the car is overheating, and the heater is COLD there is AIR trapped in the system. Turn the car off and let it cool down. Massage the upper hose. It should get hot. Once the car cools back down, start it again and keep filling. Some 2.0s seem to catch a lot of air. This is somewhat normal, and may take several cycles with a full empty system.
If the car is overheating, and the cooling fans are NOT working. Check to see that the thermo-switch in the radiator is hot. If its cold, the fans will never turn on, and the system has air trapped in it. If the switch is hot, make sure coolant has not dripped into the fan control unit (under the coolant bottle). A really dumb place for a piece of electrical equipment. Another trick is to turn on your A/C. This should also turn on the cooling fan.