Forum:
I have a 88 e reg fourtrack , good as gold , but for the temp gauge sometimes gets near , never in the red.
new water , antifreeze , stat , rad cap all fitted new, its normally when under load, ie towing , or 70mph plus for 30 miles ish , any ideas 
other?
hiya chris i semed to av same prob back long n done all the same you say u av new rad cap n the likes. mine turned out to be a knackard radiator it never leaked. but when tested found it had corroded and was giving a bad flow rate. gave it a good clean out with radiator cleaner and reversed flushed it n seemed to cure my over heatin probs. with regards ..... woody
If it's a petrol engine, chec
If it's a petrol engine, check the ignition timing and vacuum advance operation. I had the two vacuum hoses swapped around so the timing retarded when it should have advanced.
The engine would idle for hours without overheating, but as soon as I tried to do 50+ the temp would start to climb.
If it's a diesel, it'll probably be the raditaor, judging by the age and everything else you've checked/replaced.
Have a look at this page htt
Have a look at this page http://www.daihatsu-drivers.co.uk/node/788
Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.