P38 2.5 Dse Cooling Problem

Hi, I've got a 97 2.5 DSE with 137000 on the clock. I've had the car for about 6 months and done about 7000 miles with no problems. Recently on my way home from work I pulled out onto a dual carrige way and lost all power. When I tryed to pull away again it started to go but then just died again. At this point I noticed the temp gauge was in the red. As i was on a dual carrige way i carried on for about half a mileat about 5mph so that i could pull into a lay-by. I dicovered that I had blown a water hose going from the engine to the heater box. After a quick fix I was back on my way. About a week later I noticed my heater wasn't getting hot and that the temp gauge had hardley moved from the blue and that the coolant hoses had pressurised. I haven't got any signs of any water in the oil or oil in the water. Lately on start up it seems to crank over for longer than usual and chucks out a load of black smoke. the engine seems to be a lot tappier than usual. Could this be my head gasket or cracked head, or maybe dodgy injectors. Any ideas please?
Karl

Doesn't sound good at all, seems to be cooling system related on first glance.

Are you able to strip the parts (thermostart, water pump, viscous fan, radiator) and replace them yourself?

They are low cost items (compared to a new head/block anyway), it's the labour charges and loss of use which could be the killer.

I was thinking along the lines of a cooling problem, maybe an air blockage or water blockage. lucky i can aford for it to be off the road for a while so I can investigate. I'll try those parts first. I'm just preying it's not the head gasket or head gone. I'll let you know how iI get on.