So this is weird. Normally I have music on but tonight I didn't, and in the eery quiet of the cabin I noticed a slight whirring sound in addition to the normal ticking of the engine. I opened the door and got out with the car running (in Park) and could also hear it. It seemed more prominent on the passenger side.

It was about 38 degrees F and fairly humid. The fan was on slightly inside the car but I could hear the whirring even more clearly when I turned climate control off.

While I recognize this is probably normal and I am just being a vehicular hypochondriac, it does concern me a weeeee bit. On the other hand I noticed a hum in my 97 4Runner at about 38 mph and the dealer techs told me to their astonishment that all the 4Runners did it but no one had noticed or mentioned it until I did. I never did have a transmission problem with that truck in 17 years of use.

I will be interested to know if anyone else has heard this.

 

Nope. I drive deliberately with the sound system off sometimes to enjoy the quietness of the car and also ensure no such noises exist.. I am usually sensitive to such noises (e.g. the low whine of my 14 Altima electronic steering).

 

Your description sounds like the noise that I hear after the engine restarts after an idle stop. I think it's the engine cooling fan; for me it goes away once I get back to normal road speeds.

 

That sounds plausible, although it was hard to localize it at the front of the car. Oh well, we'll see...

 

Did you ever find out the cause of the sound? I am on day 2 of my new TLX and I hear the same sound. I know I didn't hear that sound when I test drove a different TLX at the dealership. Any info is appreciated.

 

Well the whirring went away at about 170 miles or so. I guess it was something that needed to wear-in somewhere.