My 02 Tundra started over heating while I was pulling a load. No dash light or sensor came on. I have thus far installed new water pump (because it was due to change anyway) OEM thermostat, OEM clutch fan, after market radiator. I installed the radiator about 6 months prior to having this issue. I let it idle for at least 30 mins the other day with no issues. Today I drive it for about 15 mins and the gauge starts to rise. I have been fighting this issue for about a month now. What else could it be. Still no sensor light.