I have a volvo penta V6 4.3L that seems to run cold I just bought the boat and thought that the temp gauge was not working but I puled the temp sensor out the resistance was good so I then boiled some water plugged in the temp sensor and put it in the hot water the gauge did read temperature fine. I checked to see if the thermostat was stuck but seemed fine alittle corroded so I installed a new one, still boat runs real cool and indicator never goes off full cold. I seems to run just fine plenty of power and speed. Should I be concerned about this ?