Here is the problem, car has sat for about 2-3 months. 91 teg-LS btw. I just decided to start driving it again. When i turn the car on, temperature jumps almost all the way up.

Seems like maybe the thermostat went bad? Im going to try flushing the coolent system also. Fluid and oil are good. Fans dont seem to wanna come on. Thing is motor seems cool, nothing is steaming, nothing overly hot to the touch, radiator not overly hot. Any ideas? possible HG?

Also its very cold here in the winter, could that have done something? Ran fine when it was parked.

 

Check your coolant temp sensor. It will be a certain ohm at a certain temp. There should be a graph for it in a repair manual.