GU auto transmission cooler

[love ke70]

hey guys, dads trying to sort issues hes been having with his 2000 GU 3ltr losing power going up hills. apparently the boost does everything its supposed to, but on a long pull with camper trailer in toe it just dies. no lights come on, and he has somehow figured it must be the auto overheating.
so hes bought a big auto cooler from autobarn i think, and has been fitting it.

the question i have is, do the GU autos have a thermostat on them to keep them warm and open when they need to cool down, or do they flow through the cooler all the time?

and is there damage to be done if the oil is always running cold as he has fitted a larger cooler?

cheers, andrew

[awill4x4]

I seriously doubt it's anything to do with the auto, it's far more likely the engine is reaching an overboost condition and the ecu is going into limp home mode. If he can get onto www.patrol4x4.com there's lots of good info regarding the common overboosting problems (and many other problems) that occur with the ZD30 engines.
As for the auto, he won't harm it by using a large auto cooler in fact he will be doing it a lot of good. It may take a little longer to warm up, eg:" the torque convertor takes longer to lock in from a cold start" but it will run a lot cooler and heat is the biggest killer of an auto.
Regards Andrew.

[patrol man]

I would be looking very hard at the air flow meter, as these play up, they read low and cause over boost/ loss of power. cheers Phill.

[love ke70]

i very much doubt its to do with the auto too, but what can i do about that...if it was overheating im sure the overheat light would come on, but hey, ill let him play.

he has a boost gauge and apparently it doesnt overboost when it cuts power. which is why i cant understand the problem, it is a concern but it doesnt seem to be the afm thats causing it. i think he had it checked not long ago, and the issue only occurs a few hours into a drive on the long hard pulls.