So, the motor is back in the cooper after having the head and block surfaced. Everything is running fantastic, and no leaks! The driveway looks clean.
However, it has developed a noise that I need help diagnosing. It is not a growl, it is too high pitch. It doesn't seem to be following the RPM of the motor exactly, but close. I can get it to drop in pitch buy chugging the motor and making the car lurch a little bit.
My first thought is the transmission (6 speed manual) but it didn't have this sound before I pulled the motor, and I doubt the tranny went bad sitting in the garage. I did put new axels in. Could this sound be coming from a bad axel? I don't get any clicking at sharp corners.
Anyway, this is the best recording I could get. It only happens at a mellow pace, it I get on it a little i don't hear it at all.

 

Is there any vibration at high speed?

Does it only my make that noise near full throttle? Is the noise up front, in the engine bay, or down low to the sides, from the wheels?

If you're running a 15% pulley with a stock airbox it's possible you're just hearing the supercharger whine.

 

Regarding elusive sounds, I've been trying to locate a sound that seems to be from the passenger door. My wife said it sounded like my door.

Today and by myself, I moved my head to the center console and it sounded like the rear view mirror. I grabbed the plastic parking pass on the mirror and it stopped.

A parking pass is my problem. Ha!

Peter