Keeping cool with a load on the back.

[UKHugh]

I'm really enjoying my 3.0 2nd Gen and coming to appreciate the difference between this and our previous 2.4. However recently I've been doing some towing of reasonably substantial trailers on a few occasions and I've noticed the temperature getting close to the 'red' line on long hills and even had the ATF temp warning come on once. As soon as I let the engine speed back or get to the level it drops back to normal but I have had to top up the coolant regularly.

Reading the archives here it looks like this isn't uncommon especially for folks like me who have a bash plate on the bottom of the nudge bars. I get the impression its the ATF temperature that causes this and not actually the engine coolant. If I am going to do more towing from time to time would I get away with just getting an extra oil cooler for the ATF and fitting it in between the gearbox and the existing cooler? Or do the great folk of the forum think I should also uprate the engine cooling too? Also does anyone have and experience (good or bad) based recommendations on which equipment I should use?

Cheers all.

Hugh

[Bogus]

First and best thing you can do is to check that the viscous fan works as it should, that its got enough silicon oil in it, and that of course is assuming that the obvious like making sure airflow across the rad is not compromised in any way by mud, vegetation, insects and tat stuck on the front of your truck has already been attended to.
Then you can look at new thermostats, flushing the system, fresh coolant. maybe fit a new water pump, and finally after all that fails, extra cooling in the shape of an additional auto box exchanger.

[UKHugh]

Many thanks, that sounds good advice. I'll check all the easy/obvious/regular stuff first before I start thinking about making any changes. If all looks well I'll post back and see if there is any more I should be doing.

Cheers,

Hugh.

[shokenore]

In addition to the suggestions from Bogus I would add that an accurate aftermarket temperature gauge is a wise investment.
If you are getting in the red then you are risking cracking the head.

The viscous oil change for the fan takes about 3-4 hours and you can get the tubes of silicone oil from radio control car shops type in RC shock oil into your search engine.
I got some from eBay for less than £8 delivered 15000 cst.
Although most go for 10000 cst and I think the oem was 3000.
You could also see what temperature it locks up at and maybe drop the lock up a few degrees.

[soramad]

In addition to the suggestions from Bogus I would add that an accurate aftermarket temperature gauge is a wise investment.
If you are getting in the red then you are risking cracking the head.

The viscous oil change for the fan takes about 3-4 hours and you can get the tubes of silicone oil from radio control car shops type in RC shock oil into your search engine.
I got some from eBay for less than £8 delivered 15000 cst.
Although most go for 10000 cst and I think the oem was 3000.
You could also see what temperature it locks up at and maybe drop the lock up a few degrees.

Just to add to this my truck has never been anywhere near the red on the temp gauge but I'm pretty sure my problems were a head problem before I used the magic liquid. Incidentally my gauge is showing just below centre now where it was dead centre before.

[shokenore]

Just to add to this my truck has never been anywhere near the red on the temp gauge but I'm pretty sure my problems were a head problem before I used the magic liquid. Incidentally my gauge is showing just below centre now where it was dead centre before.

My point was that if you are regularly going into the red then you are heading for problems.
No matter what vehicle you drive running it hot and by that I mean running it into the red will do it no good.
Be it head gasket or partial sieze, or in the case of this particular head design a stress crack.
The OP has asked for advice on what to do to combat this risk, and not for sticking plasters.

With regards to your coolant temperatures, it could well be that the solution you have used has insulated the temperature sensor from reading the actual temperature or that you have topped up the coolant or are using less percentage anti freeze.

[Bogus]

I had a Hillman Minx that you could run hot to the point where you could feel the engine beginning to seize on you. A brief stop, give it a while to cool down, chuck some water in and off you go again.

[Dobbslc]

I've just added an extra digital temp gauge to my 3rd gen after doing the head,
It's sensor is installed in one of the 38mm alloy adapters you put into the top hose although its not the best fit as the hose is short and has two bends in it.
Today was hot (24°c) it read between 85° and 90° on back roads in traffic and a short motorway hop.
The toyota gauge never moves from just under halfway....
Although it's only been in a short time it does seem that the reading drops a few degrees when the tranny locks up after 55mph, I think there is something in it about the transmission heating up the coolant especially on hills and when towing.

[markp2]

We tow approx 1800kg of horsebox and trailer at least twice a week around hilly Devon.
We have fitted a digital temp gauge in the same way as Dobbsic, changed the viscous fan oil for 6000cst silicon, fitted a ATF cooler rad and use a 'snake oil' type product called Redline Water Wetter in the coolant.
I used the Water Wetter in my race car engines and it definitely lowered the running temp by a couple of degrees when competing.

All the above combine to keep our water temp at 65-75 degrees in easy running and rising up to 90-95 degrees when towing up a long hill.
The original temp gauge doesn't move off centre even when the digital one says 95!
Mark