GM 3.1L Cooling issues and cooling fan
Ok, so I've been having trouble understanding what's going on here. Vehicle is a 1995 Olds Cutlass Ciera SL 3.1L. Normal operating temp is the guage at 1/2. Lately it's been creeping up to almost 3/4 when I'm at 65-70 mph. So far, I've replaced the heater core (box was full of coolant and it smelled in the car), and just finished fixing the leaking lower intake gaskets today using the steel fel-pro ones (FUN!!). Head gaskets seemed fine, no cylinder pressure in the radiator or coolant in the oil/vice versa. New T-stat also. I'm assuming all the air bubbles are out (maybe not?) but the heat blows warm for the most part. Does anyone know the proper "bleeding" procedure for these?
Also, When is the cooling fan supposed to come on? It seems like I let the car idle forever and the fan never kicked on. I do live in Wisconsin and it's 10 degrees outside but I would think the fan would kick on. At idle, temp is fine and stays steady at 1/2. Does the fan ever come on on the freeway or is it only at idle/slow speeds? Like I said, the car never really overheats, but i dont ever remember it running like this. Any help would be greatly appreciated!