BMW Repair: 1997 318 overheating prblem, clutch fan, proper mixture

Question
my daughter is going to drive this car into the ground and cant afford to do that. I have never owned a BMW but I can work on the normal things. The thremostat has been replaced twice, water pump replaced, granted the ac doesn't work at the moment (leak in condenser) I will have to check and see if the fans work but I doubt it. The car "OVERHEATS" which tells me that it is boiling for some reason. My son supposedly bled the air out of the lines after the thermostat work but I didn't do it so I don't know. they did put new coolant back into it at the proper mixture. could it be the radiator? head gasket? I am not sure where to look next and would appreciate any suggestions you offer. Granted its to late for the "I TOLD YOU SO" but she had to have this car and now she is stuck with it so we have to try and keep it running for her on a $0 budget.
Sincere Thanks,   Dan

Answer
Checking to see if the cooling fans come on is a MAJOR important thing to do.Also check the resistance of the clutch fan to make sure it is not a free wheeling fan(means it spins...kinda)At cold start the fan should be with some resistance when turning the blade.With the a/c inop it brings out the thought that there may be debris in between the condensor and the radiator and should be cleaned out.So look into the fans they probably are not working