Offroad-Express

I have a 97 mistral the one with the dual headlights. I tow a boat and dirtbike trailer with it regularly often to altitude on steep tracks. It gets really hot at times even if I take it easy and chuck it in low on a hot day. I have done the head and the radiator is new, the cooling system is in good nic and well maintained. I did wonder about fitting an aftermarket oil cooler are kits like this available in NZ? http://www.euro4x4parts.com/parts/khk10 ... ngine.html has anyone fitted something like this or improved the cooling on a td27 that could advise? cheers in advance

Have you disconnected the trans fluid from running through the bottom of radiator before it hits the factory trans cooler? The auto trans puts out heaps of heat on the beach/ towing/climbing a hill, which serves to add heat to the water in radiator.
I find that aftermarket gauges greatly add to the accuracy of seeing what the water temp is doing. My water temp will quickly climb to 95 plus going up a steady climb (on road) for a few minutes. And i have replaced my thermostat and had the radiator removed, de cored, rodded and reassembled. I'm thinking with these mistrals and terranos the only real way to get that heat under control in these beach/towing/hill climb situations is to have a custom radiator made, much thicker than stock.

Fyi 25% loss of cooling per core. Better to go bigger then thicker. I found the y60 or vx80 rads are only 3 core but and lot bigger than old fj40/60/70 rads and cooled v8 way better than the custom rads i had made to fit the same space as the o.e.
Had to mod the front to fit etc but she dont get hot. Y60 is all copper. Vx80 have plastic tanks. That said they are still v.good

I agree with what you are saying, just no obvious room to go higher or wider in the mistral engine bay, unfortunately. And the original poster won't be super keen to have to get another radiator after buying a new one recently.

an engine oil cooler will increase the engines cooling ability.
the trouble with most stock oil coolers is they add heat back into the water your trying to cool with.
the downside of external oil cooler is they can break. not advisable to skimp on quality.

with auto's same issue with trans cooler. external is much better.

There is still something wrong you you have to go to that extent to keep it cool, mine was significantly modified on 28 psi and spent most of its time stuck in deep mud and I can count on one hand the amount of times it even got remotely hot.

is the new radiator thermally efficient like the old radiator....
is the viscous fan in good working order
are the injectors in good working order (not leaking fuel into the cylinders)
Is the intake manifold clear of carbon build up from the EGR.
what state is the turbo charger in (it might boost but is it working to its full potential (wastegate etc)

only three things will cook these motors, too much fuel for the amount of air charge, poor cooling system condition, or leaking water jacket.

I used to haul a 5 meter tandem transporter with other commercials on no problem 90 kph up hill down hill didnt matter.

haven't had injectors looked at for 100,000k so that could be an issue egr has been removed, viscous fan is working. I have a mate with a qd32 terrano and he has the same heat issues as me under the same conditions. Had the same problem with two previous trucks also, a mkI terrano and a Daihatsu rugger. Talking about towing up steep tracks to 900-1500M altitude.

If its altitude related then you need more air volume for the amount of fuel.

Does the viscous actually bite when the engine gets hot and sound like a plane taking off and you can feel it rob 5hp off the engine ?
Or just oh yea it spins around and I guess it's working

Put a cheap crappy temp sensor on /in the bottom rad hose and go test it . If that gets hot under those conditions then you know you have a rad /airflow(fan) problem

If that's well below thermostat temp then you know u have an engine problem .

I had similar issues, replaced everything, including injectors and fuel pump.
Thought my viscous fan was working fine as it seemed to spin up and pull more when hot.
Got a lazer temp gun from work one day and not much difference between top and bottom of the radiator.
Put a new viscous in and have to work it really hard now to get the temp gauge over half way now.