i have a 2003 nissan altima 3.5L v6. there is a noise coming from the water pump area. it only comes on when i turn the blower knob inside the car to turn the heat or ac on. there is a loud rumbling sound in the engine bay and sounds like the water pump area. when i drive, there is a loud whining noise that goes up and down with my rpm. does it sound like the water pump needs to be replaced since it only makes noises when i turn the ac/heat on? If i turn the blower knob to the off position, there is no noise at all from the water pump and no buzzing/whining while driving. Thanks in advance for your help!