I have 3 Lexus. My '05 makes a sort of "grinding-whirring" noise coming from the center of the dash. It's like being caused by the wind??? I have kicked it out of gear while running 55 mph, no change. I have put new tires on, no change. It does get louder as rpms go up. It's practically gone with engine running and in "P". I looked at the AC sight glass and I see bubbles all over the place.

The noise sounds like it is coming from the bottom third of the front center console.

Any thoughts? Am I losing my mind?

It's just loud enough to be annoying.

 

Is the noise is proportional to wheel speed or engine speed?

I have kicked it out of gear while running 55 mph, no change.....this indicates it is not related to engine speed.
It does get louder as rpms go up.....this indicates it is related to engine speed.

Turn on and off AC to see if it is AC related....

 

I'll do more investigation today. Thanks for the tip. I believe it is related to engine speed.