Hello,
My 2003 GMC Sierra 1500HD with the 6.0 has a fluctuating temperature gauge. It doesn't appear to overheat and the gauge doesn't read that it is getting too hot, but just seems to move more than it should. When at operating temperature it seems to move from 180-200. It will go back and forth from one to the other and sometimes stay cooler then hotter... The thermostat and water pump were replaced very recently along with the mechanical clutch on the fan. I am thinking this is the mechanical clutch coming on and off, but wanted to see if others have the same thing in their GMC's..
My 2003 GMC Sierra 1500HD with the 6.0 has a fluctuating temperature gauge. It doesn't appear to overheat and the gauge doesn't read that it is getting too hot, but just seems to move more than it should. When at operating temperature it seems to move from 180-200. It will go back and forth from one to the other and sometimes stay cooler then hotter... The thermostat and water pump were replaced very recently along with the mechanical clutch on the fan. I am thinking this is the mechanical clutch coming on and off, but wanted to see if others have the same thing in their GMC's..