Okay, so I know that this is a far cry from a Tbird, but I am having some issues with my dads Sable. I am getting no heat. The car does not over heat, there is an intermittent sound that I believe is the water pump, however the temp is always very cool. When I get on the highway the temp gauge will actually bottom out and I will get nothing but cold air blowing from the vents. Not sure what this is. I have replaced the thermostat, coolant overflow tank, radiator cap, and misc hoses, thinking that its sucking cold air in from somewhere. Could it be the water pump? The car has a 3.0 OHC it is a 2000. any help would be awesome, its starting to get cold her in Ks.