Hum

[thom4782]

Hi everyone:

My 01S seems to make a humming sound when traveling on a highway at 70 mph. It seems like it is coming from the front, but hard to know for sure. The sound is absent when parked in neutral with the engine revs in the same range as when I'm on the highway.

The cars runs normally. A visual inspection doesn't show anything obviously wrong. The only work done on the car in the last 6 months is the front rotors and brake pads were replaced about 1 month ago.

My first impression was that the hum was tire noise on a newly paved section of the highway. Now I'm less sure. Do you think it more likely related to the brake job? If so, what do you think might be wrong?

Thanks for any insights you can provide.