I was going to say the engine cooling fans are not on, but you would have (a lot of!) heat, if your pump worked. Can't hurt to check they are running (they should trigger at M on the temp gauge). Make sure there is a plate in the housing behind the pump, it's stainless steel. The white impeller pump usually is the good type, there is also metal type (delco, autozone). You can change the pump without pulling the whole housing. The waterpump is the most common problem with the cooling system on these cars.
