whats the normal operating temp for a disco 200tdi motor? i have a cappillary temp guage fitted to the top radiator hose on mine, i have the viscous fan thrown in the bin and the fuelling tweaked as per the thread on here yet it will only read 75 even a damn good thrashing wont get it over 80. this means that i'm bloody freezing as the heater only blows tepid. are there different thermostats that i can try or is it the bodgers way of blocking half the rad off?