Scott C (QLD) replied:

Hi hotfishez,

The same thing happens with mine, temp gauge sits around half but as soon as I hit a decent hill towing the camper the gauge quickly moves toward the red, as soon as I reach the rise and back off the gauge drops as quick as it went up.

I will be interest to see the feedback.

Regards Scott

Member - 120scruiser (NSW) replied:

guys you need to install an EGT guage and set your fuel via combustion temps. It sounds as though there is too much fuel going in. Cut the fuel back on the pump by half of a flat on the screw head and see how you go.
With the 1hz and an egt you shouldn't go over 550 degrees under load flat to the boards for two minutes. It the temp rises more than this there is too much fuel going in.
I have turboed many 1hz engines and set the fuel by egt and not one has over heated.
I hope this helps
Thermogard instruments on this site is a great device. No affiliation just a happy customer

Gone Bush (WA) replied:

Same thing used to happen on my 80 series.

I replaced most of the cooling system incl radiator with no change until it was pointed out to me that on long slow inclines towing my camper the bottom radiator hose was sucking itself thin because of its age (soft).

I replaced that and filled the viscous hub with oil (they are underfilled out of the factory) and no problems anymore.

Hope this helps.

2517 replied:

Hi the best way to fix the problem is to fit a new radiator from Aussiedesertcooler.com.au ,there are about $550 landed in Darwin.Being there done that.

Steve from Top End Explorer Tours replied:

Try the viscus hub on your fan first, 9 times out of 10 this is the problem, this is cheap to fix.

Cheers Steve.

Skinnydog replied:

I have a Standard 100 series with after market turbo & glycol intercooler with pyrometer/egt meter. Before & after turbo install my air con would cut out due to over temp however both water temp & egt gauges were nowhere near critical levels. This would only happen fully loaded or on extreme Pilbara days. Then I had a run in with a failed alternator belt which was barely 12 months old and took out all belts ,top hose & the radiator,yes I was very unlucky. The silver lining at the end of this was I ended up ordering an ally radiator from PWR in QLD which was still only a 2core but was twice the thickness of the factory ally. The outcome has been better than I thought possible,the water temp has not even looked like getting to half & I have dropped 30-40 degrees on the egt, if you want further proof we recently were lucky enough to have 50+ degrees a few weeks ago so I took the opportunity to give it a flogging to really test it out & niether I or the rig broke out in a sweat.
My recomendation is to spend $1000 and fix the problem once & for all.
Hope this helps

Member - Frank (QLD) replied:

I guarantee you - there is a very good chance that all you need to do it top up the oil in your fan clutch...

Get the oil from a Toyota Dealer...

I's an easy job - I can give you step by step instructions with photo's if you want to know how to do it....

The Genuine Toyota Blue Fan Clutch which is the current OEM replacement comes with too little oil - this is the fix.

One Tube is normaly enough - sometimes they are so low they need two tubes. There is 18mils per tube.

Try one tube first - if no improvement - go with two.

Wayne (NSW) replied:

All of the overheating fixes will and do work, but you have to ask why is the motor running hot under load.

If the motor was running hot all the time, the fixes above would be the first to do but in this case the motor gets hot under load.

What causes a motor to get hot under load and cools quick once the load is taken away. Too much fuel. Under load the motor is over fueled and gets hot, back of the pedal and the motor cools.

As Scott has said install a EGT gauge and set the fuel to the gauge.

Fix the cause of the problem, and not just the problem.

Wayne