My Mini 850 form 1977 is overheating after 2-3 min of idling, or the gauge says so. I have flushed radiator and changed the fluid, and both the hoses get hot after the thermostat opens. I took the cap off and started the engine, it was bubbling from the radiator, don't know if it is air in the system or fuel gasses coming from the head gasket? I opened the heater valve and turned on the heater, both the hoses also got hot. No hot air from the heater through (I think) The rocker cover and the top of the radiator is hot, but I can hold onto it with working gloves, also all the hoses.
What might be the problem? can't figure it out.
Thanks in advance