Thread: Running hot

G'day folks
...and now for something completely different: an engine running hot.
Well, with the arrival of some warmer days, trouble is not far off. My rebuild, the 110, is getting hot. Not really in normal driving conditions, but on long runs with inclines the gauge is just nudging the red area. It never went straight into red, don't know if that's the truck's merits or me backing off the accelerator. During the cooler period of the year I never experienced these symptoms.
I have already swapped the thermostat (checked the original one and found it to be fully functioning) and the radiator (had one lying around in the garage, even here the original one looked quite good. I left it to a radiator shop for checking, though). The engine runs fine and nicely, leaks no coolant at all and the heater works as well. I have tried to get as much air out of the system as simply possible and doubt there will be much left. The engine in question is the ominous 19J, prone to blow head gaskets when overheating, hence me being very cautious and wanting to avoid this at all cost. Any suggestions (apart from swapping to another engine)?
Ta!

Did you stick a paintbrush in it?,mine worked well,never ran hot ever until I towed a load of rubbish to the tip. Pat