1997 Vauxhall Monterey engine

I should think it's just because you are ragging it! A 4x4 like this must be working pretty hard at 80mph uphill. All the fuel it is burning is generating so much heat the engine and coolant temp rises.

As long as it doesn't overheat ie temp gauge in or near the red you should be ok.

You could always put the heater and fan on to drag some heat out of the coolant.

There are coolant additives you can buy to reduce engine and/or coolant temperatures.

have you checked thermostat is working properly,and cooling fan is working,do coolant pressure test and check for leaks

thanx 4 that, but thermostat working fine n no leaks, it as a viscus fan fitted n was wondering cud it b that? ow wud i check it? i use no oil or water n av owned my jeep for yrs. i do av 2 put heater on hot n blower 2 reduce the temp wen it rises. surely this aint normal!