Strange VVT overheating problem!!

Pretty sure the fan runs all the time as its a viscous fan not electric...............unless its different on the vvt.

Jimnys have a viscous fan so it won't be that, we have the same problem with our jimny, the temp gauge goes up to the very top intermittently doesn't seem to be consistent with how it's driven but turn heaters on and it sorts out then sometimes goes back up again other times stays normal running temp for rest of journey, I've jet washed the radiator so I know that's definitely clean no mud in there, some of the fins are damaged but it's been overheating this way since few months before I cleaned the radiator out it's getting annoying now!

Mine runs at about 1/3 normal running but reaches around the half way mark if left idling for long enough. At half way its running about 90 degrees which is quite acceptable. I would suggest using a scan tool to check the sensor and thermostat.

You should also check that the fan clutch hasn't failed.

Surely the first step is to discover if it's actually overheating, or just running warmer due to the load? The needle climbing past halfway does not mean it's overheating. There may be nothing wrong.

I seem to remember posts about the viscous fan slipping I think it has some sort of internal clutch try a search there may be info on how to check it

Busta wrote: Surely the first step is to discover if it's actually overheating, or just running warmer due to the load? The needle climbing past halfway does not mean it's overheating. There may be nothing wrong.

My point is it has never done this before towing the same load and it quickly heads to the max mark before I chicken out and switch on the heater??
It's the fact that it's unusual that's making me think something is starting to fail??
I've been in to cars and was a truck driver for 35 yrs and even truck gauges don't heat up as quickly under load.
Unfortunately I probably won't be using the caravan for a few months so it might be some time before I can replicate any problem.
From the answers so far it appears there is no real answer apart from the usual overheating checks.
My first port of call would be a new thermostat but I understand this may be buried under one of the manifolds and will be difficult to replace??
My second thought is the temp sender?