if you're not overheating or not even getting high temp on your gauge that shouldn't be an immediate concern. Now, question is gaano kadami yung bumubulwak sa radiator? afaik, kung hindi naman masyadong madami or malakas ang pag bulwak normal naman may bubulwak dyan pero dapat konti lang lalo na kung sarado pa thermostat at the time of testing, paki correct na lang mga master...