Overheating troopy, cured.

Hi Boba3
Perhaps you might think about putting these details on the LCool site.
Many people there would find your experience useful as well
Ross

Long story, but 1st thing to check on an overheating 2h tojo is the clutch fan. They have a reputation for problems with the clutch fan. Pretty sure there is (or was) a complete how to including pics on the lcool site on how to replace the fluid in the fan to fix it.

From past experience it is now the first thing I would check, a good indication the clutch is gone is to listen for the fan roar when starting a cold engine, it gradually disappears as the clutch looses the silicon oil and you don't notice it, once the fan is replaced you suddenly notice that it hasn't sounded like that for a long time:)

Generally the fan will roar when you start a cold engine and disappear after a short time, no roar on cold start it's probably on the way out.

Gday
I had fan problems so the coupling was replaced . The fan never stopped roaring . What a pain, i rang the manufacturer antold the eng what was happening ,he said all was ok, but i wasnt happy with his reply and removed 9ml from the coupling , guess what , it all works like it should. I must say the eng did say he would give me another if i wasnt happy , and i wasnt so did the mods myself, three times i took the fan off and stripped to get it working the way it should. It all got back to the machine in the factory putting to much product in the coupling.

hi bob a3
I recently had a similar experience with my old mazda bravo diesel aug1996 model it has slowly been getting a higher running temp over the years
I lent it to my daughter just before last xmas but before doing so cleaned out radiator cores and fins and put in new glycol coolant the water pump was replace late 2015 so drive belts were good everything done including thermostat
but
while my daughter had it up in Perth and the weather was in the 35-40deg region
it kept getting hot and had to turn the airconditoner off
after she had finished with it and done nearly 3000ks thanks dad !
i went up and drove it home it boiled when I stopped for lunch on forrest hwy i have a watchdog on it so
got home ok
started checking out thermo fan issues the other thing was when it started cold it was making horrible clacking noises that actually sounded similar to a loose tappet but was coming from the thermo fan and as it warmed up would slowly discontinue
I compared the thermo fan resistance while hand turning it to a new ford ranger that my neighbour had just bought and found mind had very little resistance and I was able to spin mine very freely
where as his was quiet stiff to turn
I ordered a new thermo fan and installed it
what a remarkable difference now standing near the m/gard with bonnet up after cold starts the wind off the fan is blowing in my face quiet strongly and there is a whirring sound as well
the engine now runs 10 degrees cooler under all conditions
no more clacking sounds
I busted the old thermo fan open and found there was stuff all silicon oil left in it
hence the reason it wasn't turning anywhere near fast enough when the engine needed to be cooled at speed
in hindsight which is always a wonderful thing
it should have been replaced about 3 yrs ago $143 from veales
lesson learned
cheers

I have lived in Central Australia for over 40 years and have come across this overheating problem many times. A quick check to see if it's the fan, is to run the engine until it's hot, then turn it off. If the fan continues to rotate any more than one revolution after the engine has stopped, then the problem is more than likely the fan.
Most of these fans can be pulled apart, and Toyota have little tubes of silicon for about $12 or so that you can squeeze into the unit. It's surprising how little the fan needs to work. Every 4WD I own carries a tube of the silicon. (mostly to give to others with over heating probs.)

http://neuralfibre.com/paul/4wd/tuning-and-understanding-your-toyota-viscous-fan-clutch
If you go onto this site, which I've just discovered, it goes into detail (probably too much detail!) on how to go about refilling your viscous fan clutch. The report is based on Toyotos but most new vehicles have a similar system and I've only come across a couple of other makes of fans that cant be pulled apart to refill.
As the report suggests, it's hard to get the amount of silicon right (even for new Toyotos) so I just add the contents of the new tube into what ever is originally there and wack it back together. It's always worked for me and it's a lot cheaper than buying a new clutch assembly.

It's great that you've got your problem sorted - even if it did take too long.

Although my Prado is not overheating, I'm not sure that the 17y.o. viscous-coupled fan is working quite as it should. But I'm a bit curious about suggestions to replace the fan (or top it up with oil) because if the vehicle is moving a reasonable speed (ie. over 40km/h - not stuck in traffic!), I would expect the air coming through the front grille would be more than what a fan could draw through, and certainly enough to keep the cooling system doing its job. Obviously your findings suggest otherwise!

.
My 2002 Troopy was running a bit hot when working hard at low speeds such as sand dunes.
Rather than muck about trying to add silicon oil I decided to fit a new hub and did so today.

With the old hub on the bench I applied the hot air gun to the bimetal and found that it did not move the centre shaft at all. Totally frozen.
So it seems like a good decision to replace the hub at $62.