A couple of tests for you:
1. with the car running, in neutral, not moving, push the clutch to the floor. Do this somewhere quiet, with your windows down. Does the noise get worse/louder/different? If yes, suspect throw out bearing.
2. With the car in fourth or fifth, going above 25mph, go up a hill. Watch your tach. Put your gas pedal to the floor. Does the engine RPM increase rapidly/fluctuate without the car accelerating? If yes, suspect worn clutch.
Hi Turboturbo, I did both of these tests. Test 1, no noise at all, silence from Mrs Beetle. Test 2, no fluctuation in RPM and acceleration was fabulous as usual (yay turbo!). I did this test at many different speeds, varying from 40 MPH to 80 MPH on really good hills, some pretty steep (I live in the Eastern Sierra Mountains) in both 4th and 5th gears.
Are there any tests to determine if this is her flywheel(s) I am hearing? It's a whirring sound like something is spinning, and only occurs when I press in the clutch pedal while driving her.
It's not very loud, but since I got her in November, I've gotten to know this car and only just noticed the sound about two weeks ago. I don't recall hearing it before then. Is it my imagination--Could I just be paranoid something is going wrong with her?
Should I hear something when I press in the clutch while driving, or should there be silence? It's not a "grinding" sound; yet I hear something distinctly that sounds like a spinning or whirring that only occurs when I press in the clutch for about 2 seconds, then the sound ceases even while keeping the clutch pedal depressed all the way down.
