I noticed that with the engine running and the hood open, whenever I turn the steering wheel something clicks and the engine speed goes up and down slightly. Sounds a little like the click when the ac compressor goes on and off. It only clicks once until you let go of the wheel and then turn it again, then it clicks once again. Anyone know what this noise might be? The car has 40K miles.

 

The "click" you hear is the pressure sensor for the power steering system boosting your idle speed. It's normal. When the sensor detects an increase in power steering load, your engine idle speed is increased to compensate for it. If this system wasn't in place you would see your RPM's drop then you turned your steering wheel.