high temp normal ????

hi,
my jimny done some hard work 4x4 in the mountains a few days ago ,everytime theres a steep climb for more than a few minutes using 2nd and 3rd low gear temp shows about 80% on gauge and thermo doesnt seem to kick in till gauge is right up there ,is this normal for the hard work its doing to be that high ,and for the thermo to not kick in till later ????gauge normally runs at half
thanks

My Jimny seems to heat up very very quickly, even in very cold weather. It goes to mid way on the gauge and stays there as steady as a rock, even when on Motorway pulling hard. I've watched the car heating characteristics on an OBD 2 device plugged into my laptop and the heating / cooling is well tracked by the Engine Management System.

Because of the rapid heat up etc. I suspect the cooling may be marginal on Jimny's as in the manual they actually recommend reverse flushing the radiator as a routine activity. This is unusual on a standard car. Moral is keep the cooling system in very good fettle and a spare fan belt.

Jimny cooling system does seem to be a bit tempremental...but it shouldn't be doing that.

Check to see if the thermostat is opening would be the first thing to do.
Is your radiator in good condition?
2nd suspect would be the fan which apparently also causes trouble