Had been getting a consistent 'Hummmm' at around 55mph from the car, pretty much since delivery in Oct 2013. It was linked the the accelerator petal. I had heard others had the same issue and decided to wait until the new Service Center opened up on my way to work. Once they opened up they said they would give me a call once they had a 60kWh drive unit available. Just took it in this morning, now that they have the Drive unit, and they are replacing the original noisy one. Please note that this is just a low consistent Hum/growl, not the high pitched 'balloon noise' sound under hard accel, I was getting that too, so it will be interesting to see if I still have any noise under hard acceleration with the new drive unit. Once I get the car back hopefully I can get answers to the following;
-Is this just something loose in the inverter that creates extra noise when switching? or is it something mechanical in the bearings, gearing, etc.?
-I thought there was a common drive unit between the 60's and the non-performance 85's? the fact that they said they had to wait for a 60 specific drive unit seems to contradict that, or maybe it's just a firmware thing and they just had to get one with the right program pre loaded?