"Milling Noise" or "Leaking Balloon" Sound

[ljwobker]

This is nearly identical to what happened to my S85 at about 30k miles. This is definitely NOT the high-power "balloon squeal" sound, this is (at least to my ear) the "milling" sound from the drive unit. On my car, it was easy to reproduce by driving up a slight incline with power applied in the +15-30 KW range. Mine was NOT speed dependent - if I was coasting (i.e. zero-power) at the same speed the car was silent. Once I got more power on (maybe > 30KW?) it was silent. At higher speeds I could not tell if it wasn't there or just hidden by higher tire/wind noise.

In any case, if that were my car I would be insistent on a drive train replacement. My local service center must read posts here, because they actually me before I could call them. ;-)

 

[fact200]

In any case, if that were my car I would be insistent on a drive train replacement. My local service center must read posts here, because they actually me before I could call them. ;-)

Hmm...My SC has been pretty nonchalant about it to the point of ignoring it in e-mail correspondence (which included 1-2 prominent other bullet points).

Anyone actually had DU failure due to milling noise?
Have heard a rumor in an alternate thread (so many...) that they have a re-design coming early this year to fix this issue.

 

[fact200]

Just got my Late 2014 non-AP (by 3 days!) P85 back from service for various knick-knacks and the milling noise. They noted the milling sound but did not think it warranted replacement. Service advisor gave me the option of going for the DU replacement anyway or waiting 2-3 months for a fix coming "soon".

I chose to live with it for now. However upon returning the loaner (a 100K VIN S85), I regretted the choice as my DU now sounds a whole lot louder in comparison. ohwell, I'll give it a couple days to get used to.

 

[docrice]

Interesting to hear that there's another fix around the corner. I was under the impression the current "Q" version of the DU resolved this issue, but if not I'm going to wait it out.

I linked this in another thread, but I made a second video of the milling sound with the mic placed outside while driving in a parking garage:

 

[AmpedRealtor]

Just got my Late 2014 non-AP (by 3 days!) P85 back from service for various knick-knacks and the milling noise. They noted the milling sound but did not think it warranted replacement. Service advisor gave me the option of going for the DU replacement anyway or waiting 2-3 months for a fix coming "soon".

That's been the story for three years. Interesting that last quarter Elon and JB said the problems are solved and that the DUs being shipped for "the last few months" were of "excellent" quality. Is the service center saying that Elon was not being truthful, or does the service center not have the latest information? There aren't that many choices.

 

[aus]

The drop in range in cold weather is significant.
The lack of sound maybe missed for a performance car minded person.
.

 

[DDotJ]

That's been the story for three years. Interesting that last quarter Elon and JB said the problems are solved and that the DUs being shipped for "the last few months" were of "excellent" quality. Is the service center saying that Elon was not being truthful, or does the service center not have the latest information? There aren't that many choices.

In the earnings call today, Elon mentioned that they are spending much less (about 50% compared to 2013/14 and 25% of 2012 models) on honoring warranties for their vehicles. This indicates that reliability is indeed going up, and I'm assuming a large part of that are DUs. 2015 Model S vehicles were much more reliable than the older vehicles. Hopefully that is the case, I have 2 weeks until my service appointment to get my milling noise looked at and it's getting really bad. To the point that everyone getting in my car has been asking me what noise they were hearing and saying "I remember your car being really quiet...". I hope the revision DU I'll get offers a permanent solution to this problem.

 

[AmpedRealtor]

In the earnings call today, Elon mentioned that they are spending much less (about 50% compared to 2013/14 and 25% of 2012 models) on honoring warranties for their vehicles. This indicates that reliability is indeed going up, and I'm assuming a large part of that are DUs. 2015 Model S vehicles were much more reliable than the older vehicles. Hopefully that is the case, I have 2 weeks until my service appointment to get my milling noise looked at and it's getting really bad. To the point that everyone getting in my car has been asking me what noise they were hearing and saying "I remember your car being really quiet...". I hope the revision DU I'll get offers a permanent solution to this problem.

I hope you are right. Knock wood, but my February 2015 DU is doing well after putting over 22,000 miles on it. Outside of the DU issue, which I haven't had to deal with in over a year (knock more wood), my car has been totally reliable.

 

[fact200]

I hope you are right. Knock wood, but my February 2015 DU is doing well after putting over 22,000 miles on it. Outside of the DU issue, which I haven't had to deal with in over a year (knock more wood), my car has been totally reliable.

Sounds promising. I'm due for a tire rotation in another 2.5K miles (hitting 20K miles) and will prob insist on DU replacement if their fix isn't ready.

Lucky for me, the Tesla SC is only 10 mi. away.

 

[evp]

A leading theory about the Tesla milling noise is that it was caused by electrical currents being induced between the rotor and the case, which were conducted through the bearings and causing pitting.

This video talks about a series of failures in the reaction wheels in various spacecraft, the cause of which seems to be solar coronal mass ejections which were charging up the spacecraft and causing (you guessed it) electrical currents between the reaction wheels and the casing through the bearings. The problem seems to have disappeared since they started using ceramic bearings, which (I have heard) is the same thing that Tesla did in the "Q" series of drive units.

Listen to the detailed explanation starting about 4:30 here: