The thermostat has a small hole in the housing with a small pin in it, that pin must be at the 11:00 position. This bleeds air from head side into thermostat side.
Sounds like you followed the correct procedure, however you should see coolant flowing through radiator when thermostat opens. Also make sure you are using a 50/50 mixture of coolant and water, a higher mixture of coolant will affect the thermostat, since it is the water that transfers heat, not antifreeze.
Did you replace the thermostat seal when you installed it? The seal is a large O ring that fits around the thermostat, if leaking it will leak coolant around thermostat and cause it to not open, or take a long time to open.
I would try the procedure again, until coolant flows through the radiator, also quickly touch the lower hose to see if it is hot, if it is, then thermostat is open.
If you still have the problem, then remove thermostat and flush entire cooling system, you may have a blockage in cooling system.
If this is a 3 speed auto (A131L) the thermostat (or coolant temp) does not control shifting, the TV cable does, make sure it is adjusted correctly.
As KH mentioned, MAKE SURE the heater is set to max heat when filling.
Sunday, January 17th, 2010 AT 7:26 AM