bleed valve open when hot!

[Gregtenerife]

Thanks Jittsl, this is where I'm struggling to get my head round the problem. The car has only done 25000 miles and the radiators are getting hot so the circulation is ok, the fans come on and go off as they should. Ultimately I think my question is; if the bleed valve is open when the engine is at running temp. how does the system pressurise? As I am so far above see level if the system is open to atmospheric pressure the water will boil at a lower temp. So if the system is working fine when the engine is running the final heat transfer from the block with no circulating coolant may push it to its boiling point which is 10º F lower at 6000ft
I have owned a few performance cars and most of them heat up slightly above the norm because of the height above sea level and the steepness of the roads but this one has me confused.