Intermittent fault

hi guys I have a intermittent fault which is getting on my nerves now most of the time my disco drives lovely but every now and again it loses power and temp gauge shoots up I stop car turn it of wait five mins then I start it up and it's back to normal I don't know weather it's the engine or gearbox as anyone else had the same problem if so I would be very grateful for your help its a discovery 300tdi automatic 1996 2.5 Ltr

maybe if we knew what kind of disco you have(year, engine, gearbox)

Sorry my discovery is a 300tdi automatic 2.5 Ltr 1996 model

Is the coolant under excess pressure?
I've had the same symptoms before albeit on a completely different car (Ford Galaxy) - it was exhaust gas getting into the coolant. This was the first sign of head gasket problems.

try to stop the viscous fan with a rolled newspaper when the engine is hot....if you can that's the problem

Thankyou guys it happened twice today aarrrggghhh