Over heating Problem

Hey there i have a Mazda B2500 SDX 4x4 Turbo Diessel pick up and i have an overheating problem. We have removed the thermostat, serviced the radiator and also took down the engine head and shaved it becasue it was warpped and changed the head gasket. The vehicle then worked fine on the test drive and at the end just before it got to back to the garrage it overheated again.
Does anyone have a similar experience and can shed some light on this dilema?
thanks!!

Try replacing that thermostat you removed. I found that removing them actually makes the engine run hotter because the water moves through the cooling system too fast to cool it.