1996 GMC Jimmy 6 cyl Four Wheel Drive Automatic
Temperature gauge only seems to go to 160 even after installing a new thermostat. Heat is only luke warm at best. Is there any other valve in the system that controls coolant to the heater core? Is the engine temp not high enough and what else can we look for besides the thermostat?
The engine was replaced this summer, and the heat worked great last winter.
What is the new thermostat rated at? The factory unit is 195 degrees. I would measure the actual coolant temp with a mechanical gauge to see if it is actually heating up. Also check to see if your fan clutch is operating. If it is locked up the extra airflow over the radiator could be causing it to stay cool. With the engine off you should be able to move the fan, if you cannot the clutch may be bad.