With the snow the other day the driveway had to be plowed so i started up and moved the car for the first time in a little while. Its a 1990 lx with gt-40 intake as the only mod. The car started right up and warmed up to temp by the stock gauge. Everything was fine until i got in it to move it and the heater was still blowing ice cold. The first thought i had was a heater core. I was just wondering if it could be anything else before i go through the hassle of replacing the heater core.