Right then, I flushed out the heater matrix, then filled it. I reconnected the two hoses to the head. I then filled the system from the thermostat housing, I then checked the level at the rad and topped it up until it started to fill the expansion tank. I then topped up the expansion tank. Ran the engine to get it up to temp.
While the engine is running there is a steady flow of air into the expansion tank from the small y-shaped hose. The top and bottom hoses stay cold and go very hard, so much so they cannot be squeezed. I have noticed that the level of coolant in the expansion tank rises when it's running. The only part of the cooling system that gets warm is the thermostat housing. I have run the engine with the cap off the expansion tank and found that the top and bottom hoses are still pliable and still cold, but again there is a steady flow of air into the expansion tank from the y-shaped hose. Going to work yesterday the temp gauge showed that the coolant was over heating. Coming home from work this morning I left the cap off the expansion tank and the temp gauge showed normal.
Right now I can only see three possibilities 1, the water galleries in the block are blocked, 2. water pump is knackered and 3. head gasket is knackered. (however the oil is clean the water is uncontaminated, not down on power and no clouds of steam from the exhaust.
Any ideas PLEASE?