gday all ,my dilemma is i had a leak around the water pump so i replaced it and raditor thermostat heater all hoses about 2 months ago 2 weeks ago it started getting hot so ive taken the thermostat out an fitted a after market temp gadge which reads 175 f and the factory gadge reeds 1/4 my overflow bottle is raising over the max line but after an hour or so it goes back to min really hoping its not a cracked head has anyone had these issues any help would be great