I have an old 1987 525e bmw and it has a big issue with over heating, the radiator is full, after we cleaned and bled the air out. we cleaned the thermo sensors on the radiator. still over heats. what else could it be?

several options
low water in the cooling system--check at radiator cap for full radiator
blocked radiator cores --have a flow test done by a radiator shop
corroded fins on the radiator cores --replace radiator
faulty thermostat---check thermostat operation /replace if necessary
air lock in cooling system---have the air bled out
have a compression test done to check for head gasket/cracked head

Assuming the water pump is working correctly, my first guess would be air in the cooling system.
It has to be bled after repairs are made to get the air out and make sure it is full of liquid coolant.

This is usually caused by air in the cooling system. While the engine is cool, check your fluid level in the coolant tank. Then check the radiator to make sure it is full. If both of them are full, the system has to be bled. To bleed the system, take the radiator cap off, start the engine. If there is air in the system it will bubble out and the fluid level will drop, add coolant until this stops.

Easiest solution is air trapped in the cooling system. Make sure you have bled all the air out of it. If it has been properly bled then it might be your head gasket or a crack in the head itself.

make sure system is well bled of air. Open radiator cap and start engine. Run until hot and thermostat is open (coolant flowing in radiator. Keep radiator full and also open any bleeder ports on thermostat housing or in hoses until no air comes out.

check concertina hose between air flow meter and engine for splits cracks etc. check your radiator is topped up and that you have bled the cooling system, the bleed valve is beside the expansion tank.

Sounds like the thermostat has stayed closed you will need to change it as it will blow the head gasket, very common on this model.

Also when you bled it though you may have left some air in the system this would also stop the heating working, they can be a pain to bleed through keep sqeezing the water hoses as you are bleeding it through and do not bleed it from the lower part of the radiator as it will be hard to get the air out as air will stay at the top, you should bleed from the top.

No, that is not going to cause you to have no heat. You have some other problem, be sure the rad. is full. Look at your coolant temp gage if it shows normal temp you should have heat. Try and check any fuses for a blow fuse. Give us more info.

could be heating control valve ( not cheap ) or could be air in the system.