After a web search I have found the North America tech training manual from 2018 for the BMW B58TU engine online ( Plus Six uses the B58 engine ) , it explains the cooling systems operation in full, at least for the engine going into BMW vehicles. I doubt there is that much difference between Morgan and BMW in the base operation of the cooling system, the difference will be in the manufacturer/fitting/size/position of the radiators etc. It confirms that to fill the system from empty or after any repair where the coolant has been partly or fully drained it has to be undertaken using a vacuum system, you can not completely fill the system from the header tank using gravity etc. So once the header tank empties of coolant and air enters the cooling system then the system would need to be bled through using vaccum.
The manual also explains in depth how the cooling system operates, its complicated, the key design in the coolant flow through and from the engine is the Heat Management Module ( BMW terminology ). Basically a rotary valve controlled by the ECU. There is also an Electric Split Cooling Valve ( BMW's terminology ) for cooling distrubution through the Cyl head.
I have the web address for the manual, so if anyone is interested then please PM me. Alternatively, search for B58TU technical training manual online, its not that hard to find.
Last edited by Davetherave; 16/07/23 06:22 PM.
