2002 SSEI supercharged, 61K miles

There is a strange noise I've noticed coming from (as best as I can deduce) the passenger side rear quarter of the car.

The noise, as best as I can describe, is a very high pitched whinning sound. Not a grinding noise, it is very consistant, it SOUNDS like a motor or some other high RPM device. It is NOT the ride leveling compressor, I can hear that working correctly when I first start my car, and that noise is a deeper almost chuggin sound which goes away within 10 seconds. I hear the sound when the car is on, moving and varing RPMs do not affect the sound. It is intermittant, although if I hear the noise it will continue until I park the car for an extended period of time and it cools. It seems that it happens when the car gets hot, and it almost certainly happens if I drive for an extended period of time.

If the noise starts, and I park the car and turn it on and off, the noise will start again when I start the car. But, if I allow it to sit and cool, it will go away.

I have crawled under my car several times, and I cannot for the life of me figure out what it is. Every gearhead I know can't diagnose it.

Any help will be much appreciated.

-Sam

Sounds like a brake or a wheel bearing. Jack the car up and spin the tire by hand. Look and listen. Grab the tire by the 3 and 9 o'clock positing and check for any movement when you push in on one side and pull on the other. If you have wobble..it'* the wheel bearing for sure. Pull the tire and check the brake caliper and look for wear or unusual marks on your rotor.

Thanks for the response Purple.

The noise happens regardless of movement, driving or sitting still, just as long as the car is on. It is as if some mechanism is turning on when the car gets hot.

I guess I should have put in my original post, there may be nothing wrong with the car, I just want to know what this is.

The only things that could make that noise from the area that is electrical would be the ELC compressor or the fuel pump.

Since I did not know where the air compressor was, my first thought was fuel pump.
After my car sits over night when you first turn the key to run, you will hear the fuel pump pressure up the lines. As soon as it has stopped I turn the key to start. Try that next time. Turn the key to run, not the start position, and see if it makes that sound. It should for a few seconds and then stop.
It seems to me the older the fuel pump gets the louder it gets too. The pump sits in the tank and if you lift up the carpet in the trunk you will see the access plate behind the rear seat on the passenger side. You could also take the plate off and have someone turn the key to run while you listen in the trunk. Good luck,
Mike
Mike

FIXED
I took the car into my mechanic on another piece of maintenance and I mentioned the noise to him. He spent a little time with it and informed me that the car still had its original fuel filter (which I was told was replaced regularly...ha) and he suspected that the fuel pump was working hard and making some noise when it got hot. He put in a new filter, no noise, good to go.

Thanks for weighing in.
Sam

Great news! Thanks for letting us know what the solution was.