99 GU 4.5 AUTO low range temps

[04OFF]

X3 on the thermostat, I think they are about $60 for a tb45, but at least you know it works, and opens at the right temp.

[jff45]

The most useless instrument in the Patrol has to be the temp gauge. Anything not in the red is normal.
You need to get an Ecutalk and see exactly how your engine is behaving. By the time you pay for rad clean, fan clutch & thermostat, which might or might not be necessary, you won't be far off the cost of the Ecutalk.
Get a temp gauge on your auto trans and see if you're not pumping over 100 C through the bottom of your rad in those conditions..

[jay see]

X 2 with using an OE thermostat, as I have copped a bad after market one, before. Since then, I test any new thermostat I fit, by placing it in a pot of boiling water. It doesn't take too long, for the thermostat to open.

That's my way of checking if it's working or not.

[Hilux]

Well after Replacing Thermostat, Water pump and Clutch Fan Turned out that it was the Radiator. The water pump had a leak im guessing the last owner put some kind of chemi-weld to stop the water pump leak and it blocked up the radiator. Now I can Low range in luxury with the aircon flat out. leave idling in 34 degrees outside and the temp hasent moved past halfway. For some reason seems to run a little cooler with Gas rather than petrol. Thanks for everyone's input im pretty sure the clutch fan was gone also but at least i have the whole cooling system done.