I just bought a 1995 chevy Lumina and it has a grinding noise coming from the engine. It only gets louder as I start the car or put it in park. I also had a heating issue with it. The tempature goes up but never hits the red mark. I changed the water pump and the thermostate and it is still doing it. It has never over heated but when I first start the car in the morning it will shoot up to the hot section then will go down and keep on going up and down. Can anyone help?