My '99 model 2388 chewed out another water pump (it was only 2 seasons old) a few days ago and got rather hot but did not boil any coolant. We replaced it and the fan belt (usually shred about 1 per year of those also!) re-filled coolant and expected to get going again. Within about one minute of harvesting the temp gauge was on the edge of the red again, so stopped and tried to cool down the engine but it didn't want to drop, even on idle on a cool day. Now we have tried just about everything we and all the local service guys can think of to stop this occurring but it's still getting hot with virtually no load on the engine and cool weather. We have removed the radiator and had rods through every core, flow tested to check, replaced the thermostats, radiator hoses, cleaned the rest of the air-box components, replaced the oil cooler heat exchange as a small amount of raw oil was found in the radiator, checked the water pump spins freely by hand and that the belt is driving not slipping. After all this and the temp gauge still sits in the red so, using one of those laser temp testing guns we found the following readings in degrees Celsius; radiator top tank - 65, radiator bottom tank - 25, Cast iron thermostat housing both above and below the actual thermostats - 95 approx! It would appear the radiator is fine but the coolant flow is restricted , or could we have an air lock somewhere stopping coolant leaving the block? Don't know where else to look! Forgot to add there are no air bubbles whatsoever in the top tank that might indicate a blown head gasket. Thanks for any help.