BMW Repair: coolant flow bmw(e34) 94 525i, bmw e34, radiator cap

Question
I can't get the coolant to flow completely through the colling system. I've replaced the following: waterpump,thermostat w/housing & now the radiator.Bled,bled & rebled the entire system. The radiator gets hot on the side with the upper hose (driver's side) but stays cool on the lower hose(passenger)side. No heat available either. As if the T-stat wasn't opening.PLEASE HELP!!

Answer
How are you doing Joe!
Allow me to be of better help to you by answering the following questions first:
a) Just how do you do your bleeding?  Chances are that you are doing it right, but I just want to be sure.
b) What made you say that the coolant does not flow completely through the cooling system? Don't get me wrong, I just want to make sure, that we are on the same wavelength. Is your engine overheating? You have failed to tell me the most important thing relating to your cooling system's proper functioning. Also, pls. note that the hot coolant from the engine is normally hotter by at least 20 degrees
centigrade (on newer radiators, as much as 60 degrees hotter) than after the radiator has done it's job of cooling the coolant.
c) Your particular car/model has one of the most circuitous
cooling system as you may have noticed with a lot more hoses
and connections than most cars. Could you furnish me with the last 7 of your VIN numbers?
d) When you replaced your radiator, and naturally removed your expansion tank on the left side( the plastic part where the radiator cap goes on), did you notice a thermostat-like part at the junction of the expansion tank and the radiator?
e) Please run the engine with the heater on, then feel the secondary water pump motor if it is also running (this is the small cylindrical motor at the left side of your engine compartment near the firewall). Do you feel it running?
f) Are the cable connectors/wires visually OK to the secondary water pump and the valves (to which the hoses of the pump goes to)? If it is not running, is there power present in the wires going to the secondary water pump when the engine is on and the heater on?
Your answers to the above questions can help us properly diagnose your cooling system (though  some more questions may have to be answered).
Tino