I have a 1987 325i that i am trying to bri...

If you have blead the air from the system then its a Clogged radiator. When an engine gets old then particals of rust build at the bottom of the radiator core. The reason for this is the hot water comming from the engine goes in the bottom pipe and back in the top pipe the core of the radiator acts as a strainer. When you look in the top of the radiator it look's ok but is clogged at the bottom. As it is particals of hard rust radiator flush can't disolve them you can even wash out the system until the water is clear but the hard rust will still be stuck in the core. I have tried all rad. flush power washing etc. It may help a bit but not a cure. You will need to replace the radiator. Hope this help's Cheers