NewHilux.net

Watch this thread as I'm having the exact same issues just bought new coolant and fan hub oil today to try fix the problem

It has been a while since I have checked the fourums and posted an update.

Here is what I did.

I replaced the fan clutch. No obvious improvement. This was always the issue with my old ute and aleasy fixed any over heating
I also replaced the thermostat
I developed a coolant leak around the water pump seal so replaced the pumps as well
I dod a flush and I put new coolant (Nulon) at a 50/50 ratio. This was the max recommended on the Nulon Bottle.
Lastly I brought a new Radiator from Repco at when they had their 30% off sales.

This was all during the Winter so It was not until this summer that I got the chance to test it with the camper in tow and on a hot day.

The result is that it has improved things but only just. Towing on a 40 Degree day and sitting on 110 km/hour the coolant temperature reached 103 degrees. This is right at the temperature that the Air con cuts out. But the AC didn't quit. But it was right on the edge.

So having invested several hundred dollars and hours of my time I would suggest I improved it just a little. I suspect that the radiator was the largest contributor to the very small improvement.

If I was to go through the pain again i would get a new Denso radiator, but the Automatic version and put that in as it looks like it has twice the cores and no doubt would cool the manual much better.

I am still not happy but as it is a rare event that I tow on a 40 degree day I will live with it until the Ute gets traded on a new one. When that will be I don't know..

Not saying that the cooling is always adequate, but I wouldn't be towing anything much at 110 on 40degree days.

It's not just the engine that gets hot. The heat generated in diffs and gearboxes can be pretty high also. The radiant heat punching off the road into all the mechancal bits just a bit above the road does no good to anything.

Why do you need to sit on 110 . Try dropping back to 95 or 100 . Maybe your asking to much out of your little 4cyl .

I would imagine towing at 110kph would be generating some pretty high egt's - that would be the probably cause of the heating issue. If it was 110kph with no van I would say you have an issue but towing on a hot day at a higher speed will generally give you grief in the cooling department.

My brother took a tandem ski trailer down to the bite for jet trek in February. Dual cab diesel with a canopy and two skis on - Called me to ask why his car was getting hot....... 43 degree day, air con on doing 120+...... wondering if it was the radiator duh! You flog a car long enough and hard enough and no amount of cooling is going to get the heat out.

Car should be able to tow the max rated load plus a ton in the back (gcm) with the ac on at the speed limit in any temp that could be expected in the country of sale.
I think I might be up for a new rad after seeing 98 degrees today with 40 degrees intake temp. Was only towing just under 700kg.
Did anyone try the auto radiator in a manual?

Has anyone used (Evans waterless coolant) in there Hilux my mate uses it in his rotary engine it runs a lot cooler then ordaniry coolants just a heads up search it up on google or YouTube results are very good

I had the same problem when towing on hot days it would cut out mostly at 100km had it under warranty so toyota did everything they changed everything even my ECU they said it was faulty in the end same thing took it back ended up being the radiator and like you said only a little improvement it is due to the lights so I'm doing another change and useing your idea getting an auto radiator from denso and plugging it surly has to work better.

Just thinking out loud, but has any tryed an oil cooler for the engine oil?
Mite help.

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There is some sounds advice here:

viewtopic.php?t=24386

I would lower the glyco (coolant concentrate) to water ratio say to 33% to 67%. Water has a higher specific heat capacity than glyco. That means more heat will be tranferred away from the engine if flow of coolant is maintained as constant. This is the reason why toyota recommends not to have concentrate at more than 60% or cooling efficiency will be compromised.

Why plug the tranny cooler on the auto radiator if used in a manual? it wont leak.

Is anyone looking at your EGTs while towing on at hot day at 100km/h?

Note to self again, never buy a vehicle that has a history of towing.

My 2011 V6 auto tows semi-regularly. Has had an intercooled Supercharger on it for over 12 months now punching out in the vicinity of 250kW and 700nm, just approaching 120,000km. Still has the original radiator, and has been log book serviced (by time not km as I don’t do 10,000km per 6months). Has had an aux cooler on the auto since less than 1000km. Has never gotten hot, even towing rated towing capacity at 40deg+ days giving it a caning up hills overtaking slow diesels towing vans. So the auto radiator must be good, that or the little diesels have a problem developing too much heat. Note that my aircon stays on full cold all year round, I like the cabin under 18deg regardless of outside temp, it has never cut out. Has a bull bar on it too, plus the intercooler and auto cooler in front of the aircon condenser.

First post so be gentle...
One idea is to add an extra bottle of silicon oil to your viscous fan hub. They come apart easily. We do it at work (underground Landcruisers) all the time. You can actually add two bottles but the fan will be very loud as it will be driven almost constantly

hiluxxury wrote:Is anyone looking at your EGTs while towing on at hot day at 100km/h?

Note to self again, never buy a vehicle that has a history of towing.

My 2013 sr5 auto sees between 250-350c egt towing 2.5 tonne @100 kmh and up hills I back off at 500c and the truck keeps chugging on at more or less the same speed. Use the gearbox and i always tow in 3rd and manually change to 2nd on the steepest hills. Keep the revs at a sweet spot of 2500-3500 This applies to manual transmission also!

Nothing wrong with a vehicle with a history of towing as long as the owner looked after it.

toyotas fan clutch fluid is rated at 10k weight. when i had the fan off doing water pump i topped fan up & added a bit of 30k weight silicone oil. its available from radio control hobby shops.
in general driving the ac never cuts out now. only time it has ever cut out since was towing a loaded car trailer up the blue mountains in 40deg heat. which id expect it to get hot!
in freezing cold winter however at stationary idle the temp drops to about 1/4. driving is fine stays just under half.

You have not heard a noisy viscus fan till you have one fail in the middle of harvest in summer with no spare parts.
20min later the hub had been out, cleaned, filled with silicone and 4 holes drilled straight through and bolted solid for good measure. Then back in.

Too say I didn’t have a cooling issue anymore was a understatement.
Did have a loud noise issue from then on though. The radio had to go up a little louder



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Hi jplozza,
Hey man, I have been reading through this thread. The problem you have is identical to one I am currently going through with my lux. I have a 2010 dual cab KUN26r 3.0L D4D Manual.

I was wondering if you sorted this out and can advise what the final diagnosis was?

Cheers mate,

hi there
A few months ago I sold my triton mn which like normal has cooling problems , when towing my van it would reach over 100c . so I started to try different things and found that bulbar don't help and tried a bigger radiator, and went back to the original one .
so I took the shroud off bottom and top and placed part of the top shroud for safety. and replaced the thermostat with a tridon brand and also placed one scoop either side under the front forcing air to the bottom of the radiator while traveling. my temps would than range from 83c to a max of 89c which I was satisfied with these temps .and I had the ecu up graded before this issue and also had a exhaust temp gauge and a e gauge .I hope this may help with your temps . I believe what was the most help was removing the shroud which helped to allow more air to ventilate through the radiator .
I only needed a two wheel drive car so I purchased a 4ltr Hilux the triton was a good vehicle and did many mods which made a better ute .