ALL POSTS - motor whine or "HUM" (Milling Sound)

[cossie1600]

My car has 7000 miles on it, I am starting to get the hum, especially at 75mph+. Plus as I have more wear on the tires, the car has gotten much noisier. I don't know if the cold weather factors into it too?

 

[cwerdna]

With so many reports here and numerous ones on TeslaMotorsClub w/the Model S, it makes me wonder about the long term durability and reliability of the gearbox/drivetrain.

I wonder if more of these will crop up (w/both the Rav4 EV and Model S) after the warranty's up --> too bad or someone eating the cost to replace these outside warranty. The latter can't go on indefinitely.

 

[qwk]

With so many reports here and numerous ones on TeslaMotorsClub w/the Model S, it makes me wonder about the long term durability and reliability of the gearbox/drivetrain.

I wonder if more of these will crop up (w/both the Rav4 EV and Model S) after the warranty's up --> too bad or someone eating the cost to replace these outside warranty. The latter can't go on indefinitely.

This is a non-issue. I have driven many Model S cars including my own, and some have the hum, but it's not that noticeable. After 13k miles in my car, a few thousand in others, and having been in the auto repair business all my life, I can say with confidence that the Model S will last much longer than any other car on this planet, and need fewer repairs. Sure there are some cars that have problems, but no mechanical/electrical product in the history of mankind has been flawless.

Now, if I had a Leaf , I would be stashing cash for repairs, because it's inevitable(heater, battery pack).

 

[cwerdna]

With so many reports here and numerous ones on TeslaMotorsClub w/the Model S, it makes me wonder about the long term durability and reliability of the gearbox/drivetrain.

I wonder if more of these will crop up (w/both the Rav4 EV and Model S) after the warranty's up --> too bad or someone eating the cost to replace these outside warranty. The latter can't go on indefinitely.

This is a non-issue. I have driven many Model S cars including my own, and some have the hum, but it's not that noticeable. After 13k miles in my car, a few thousand in others, and having been in the auto repair business all my life, I can say with confidence that the Model S will last much longer than any other car on this planet, and need fewer repairs. Sure there are some cars that have problems, but no mechanical/electrical product in the history of mankind has been flawless.

Now, if I had a Leaf , I would be stashing cash for repairs, because it's inevitable(heater, battery pack).

I wouldn't be so confident about that. I've seen what reliable looks like (e.g. from Priuschat), including following the nature of problems from the launch of Gen 3 Prius (2010 model year, began shipping in ~May 09) including any 1st model year teething issues from that. And, I've seen unreliable (e.g. cruzetalk.com and its associated horrible CR reliability reports). Even engine and transaxle failures on Gen 2 Priuses (04-09 model year) now are fairly rare. Usually the engine replacements are due to very high mileage or running out of oil. (I have a link at http://prius.wikia.com/wiki/Lifespan/Operating_costs to 2 fas 4 u who was at 465K miles on his 09 Prius before he traded it in for '12 Prius v wagon in January 2012. His v is somewhere past 265K miles now (http://priuschat.com/threads/prius-v-200-000-miles-club.128127/page-3#post-1920242).

As Tony will attest to, there have been 0 or virtually 0 '11 and '12 Leaf motor replacements. I can't think of ANY Gen 3 Priuses that needed new engines nor transaxles on Priuschat, let alone in the 1st year or two of production. In comparison, I see numerous motor/powertrain replacements on the Rav4 EV which sells in TINY quantities vs. Priuses. And, I see numerous ones on "TMC" (hate that acronym, as it also stands for Toyota Motor Corp.)

And, for the Model S, I've seen add in needless complexity such as the door handles that extend and retract that do fail. Almost nobody else does that. The last time I visited a Tesla store, I saw at least 1 car on the floor that had malfunctioning handles. The battery pack failures on a Model S seem just as inevitable on the Model S, as a bunch of those and some on the Rav4 EV needed to be replaced. Very few Leaf battery packs have been replaced (except for those in hot climates due to the Leaf's lack of TMS). As for heaters, the failures didn't seem that common on the '11 and '12 Leafs. It seems like the OBC on those Leafs was a weakness.

Tesla's new to building cars from the ground up. They don't/didn't know what they don't know. If they care about quality and reliability, once their cars out there in the field long enough, they will learn their lessons and put the right processes in place. Others have been building cars for more than 100 years.

 

[qwk]

With so many reports here and numerous ones on TeslaMotorsClub w/the Model S, it makes me wonder about the long term durability and reliability of the gearbox/drivetrain.

I wonder if more of these will crop up (w/both the Rav4 EV and Model S) after the warranty's up --> too bad or someone eating the cost to replace these outside warranty. The latter can't go on indefinitely.

This is a non-issue. I have driven many Model S cars including my own, and some have the hum, but it's not that noticeable. After 13k miles in my car, a few thousand in others, and having been in the auto repair business all my life, I can say with confidence that the Model S will last much longer than any other car on this planet, and need fewer repairs. Sure there are some cars that have problems, but no mechanical/electrical product in the history of mankind has been flawless.

Now, if I had a Leaf , I would be stashing cash for repairs, because it's inevitable(heater, battery pack).

I wouldn't be so confident about that. I've seen what reliable looks like (e.g. from Priuschat), including following the nature of problems from the launch of Gen 3 Prius (2010 model year, began shipping in ~May 09) including any 1st model year teething issues from that. And, I've seen unreliable (e.g. cruzetalk.com and its associated horrible CR reliability reports). Even engine and transaxle failures on Gen 2 Priuses (04-09 model year) now are fairly rare. Usually the engine replacements are due to very high mileage or running out of oil. (I have a link at http://prius.wikia.com/wiki/Lifespan/Operating_costs to 2 fas 4 u who was at 465K miles on his 09 Prius before he traded it in for '12 Prius v wagon in January 2012. His v is somewhere past 265K miles now (http://priuschat.com/threads/prius-v-200-000-miles-club.128127/page-3#post-1920242).

You are taking a few cases out of many and assigning reliability based on that? Lol. The I knew of someone, who knew of someone theory doesn't hold water. Also comparing an ICE vehicle with hundreds of moving drivetrain parts to an EV that has a fraction, is silly.

As Tony will attest to, there have been 0 or virtually 0 '11 and '12 Leaf motor replacements. I can't think of ANY Gen 3 Priuses that needed new engines nor transaxles on Priuschat, let alone in the 1st year or two of production. In comparison, I see numerous motor/powertrain replacements on the Rav4 EV which sells in TINY quantities vs. Priuses. And, I see numerous ones on "TMC" (hate that acronym, as it also stands for Toyota Motor Corp.)

Again, a leaf has a fraction of the power of the model S. Not only that, but the nissan motor is a more or less off the shelf part, while Tesla is not only designing and manufacturing theirs, they are pushing the envelope in all categories. As for the Prius, again apples to oranges, and data from a forum is a tiny sample. Do you seriously think if your leaf had a slight hum, Nissan would replace the drivetrain? You cannot be that naive.

And, for the Model S, I've seen add in needless complexity such as the door handles that extend and retract that do fail. Almost nobody else does that. The last time I visited a Tesla store, I saw at least 1 car on the floor that had malfunctioning handles. The battery pack failures on a Model S seem just as inevitable on the Model S, as a bunch of those and some on the Rav4 EV needed to be replaced. Very few Leaf battery packs have been replaced (except for those in hot climates due to the Leaf's lack of TMS). As for heaters, the failures didn't seem that common on the '11 and '12 Leafs. It seems like the OBC on those Leafs was a weakness.

I will give you the door handle complexity argument, but please remember that Tesla regularly revises and re-engineers parts, while their automotive counterparts just stuff the same old failure prone part in, just to have it fail again.

The main difference is that Tesla not only makes better cars, they will fix issues under warranty no BS. Nissan either blames the owner, or kicks the can down the road. That's the reason Nissan parts aren't being replaced. It certainly isn't because of a lack of failures. This should be evident for someone like yourself, who reads forums.

Tesla's new to building cars from the ground up. They don't/didn't know what they don't know. If they care about quality and reliability, once their cars out there in the field long enough, they will learn their lessons and put the right processes in place. Others have been building cars for more than 100 years.

100 years of experience doesn't mean competence. IMO, Tesla's quality makes most other manufacturers stuff look like cheap Chinese bootleg junk(especially the US big 3).

 

[cossie1600]

I have to say the quality on my leaf seems to be better than my rav 4, but it's functions are very limited.

 

[cwerdna]

Qwk, you seem to like to explain away or give excuses as to why it seems Teslas aren't very reliable or should be given a "free pass".

You are taking a few cases out of many and assigning reliability based on that? Lol. The I knew of someone, who knew of someone theory doesn't hold water. Also comparing an ICE vehicle with hundreds of moving drivetrain parts to an EV that has a fraction, is silly.

Go take a look at Consumer Reliability reports year after year for Toyotas and Hondas (along w/their luxury nameplates) for every model year over every model. There are very few of them that have below average reliability and most are above average, if not much better than average. I've seen what the types of issues that reliable vehicles have.

On the other hand, before any reliability results for the Chevy Cruze came out, I saw all sorts of problems from numerous folks (e.g. transmission problems, coolant leaks and smells, improperly gapped spark plugs, speedometer spiking while the car's standing still, etc.) No surprise that when the stats came out, it was the worst vehicle in reliability in its class. The next year, it improved to average for one or both engines. But, then it deteriorated again. Seemed like a pretty good correlation to me.

When I had a 04 Nissan 350Z and saw problem reports on the 03 my350z.com (and from a coworker w/an 03), the problem spots commonly reported closely correlated w/CR's reliability reports. I personally experienced some of the issues commonly reported (e.g. axle click (was a TSB for that, service writer diagnosed it was that right in front of me), front tire inner edges feathering (was a TSB for that + alignment warranty extension w/tire replacement in some cases, I got mine front tires replaced under that + an aligment), both power window motors failing (replaced under warranty w/o issue), etc. I had some valve cover oil seepage too (fixed under warranty).

As for "comparing an ICE vehicle with hundreds of moving drivetrain parts to an EV that has a fraction, is silly." well, gee, it seems that the one w/way more moving drivetrain parts can last much longer w/o replacement.

Again, a leaf has a fraction of the power of the model S. Not only that, but the nissan motor is a more or less off the shelf part, while Tesla is not only designing and manufacturing theirs, they are pushing the envelope in all categories. As for the Prius, again apples to oranges, and data from a forum is a tiny sample. Do you seriously think if your leaf had a slight hum, Nissan would replace the drivetrain? You cannot be that naive.

As for Leaf having a fraction of the power, that doesn't make the motors from Tesla reliable nor is it an excuse.

There are plenty of reliable vehicles w/way more horsepower than say an econobox, yet they're still reliable.

As for "nissan motor is a more or less off the shelf part, while Tesla is not only designing and manufacturing theirs," who is supplying it? http://www.youtube.com/watch?v=xPKRTQbLs0w shows manufacturing and mentions Nissan was manufacturing them in their plant in Yokohama. I'm pretty sure they still are for JDM and other Asian market Leafs. How about now in Smryna w/trials in 2012 at http://www.youtube.com/watch?v=ZPs7FTAKTxU?

I haven't bought the paper at http://papers.sae.org/2011-01-0350/ titled "Development of High Response Motor and Inverter System for the Nissan LEAF Electric Vehicle".

while their automotive counterparts just stuff the same old failure prone part in, just to have it fail again.

That's a bunch of bull.

Nissan either blames the owner, or kicks the can down the road. That's the reason Nissan parts aren't being replaced. It certainly isn't because of a lack of failures. This should be evident for someone like yourself, who reads forums.

More bull. I've owned 1 Nissan for ~3 years, another for ~8 years and am leasing a Leaf now.

Sure there are bad dealers and service departments (as there are for all the other automakers), but your assertion is not true from my experience and what I've generally seen.

100 years of experience doesn't mean competence. IMO, Tesla's quality makes most other manufacturers stuff look like cheap Chinese bootleg junk(especially the US big 3).

On your 1st statement, true. Ford has horrible reliability now. On the other hand, Toyota and Honda have pretty good reliability and they've been building cars for many decades.

Tesla's quality and inexperience doesn't really give me any warm and fuzzy feelings. Sure, the Model S has great range, incredible acceleration and great handling, but it doesn't look like their reliability is great. It seems like the bits they supply to Toyota are largely responsible for the Rav4 EV's poor reliability, so far. And, we have no long-term reliability stats yet.

 

[qwk]

Like I said, forums are are not a definite indicator of anything. I'm not making excuses for Tesla, just stating my experiences and others I know(who actually own the car).

Obviously you have 0 experience in engineering and racing, or you would know that more power almost always results in less reliability. Simple physics.

Is this an example of the proactive warranty replacements made by Nissan you are talking about? Lol. Just face it, the current auto manufacturers have no interest in customer service. Once you buy it, and have problems, anything can happen. Note that multiple people had problems with the repairs of the same problem, so no, not an isolated incident.


http://www.mynissanleaf.com/viewtopic.php?f=30&t=15372

It's a given that Japanese automakers have better reliability than the Bailout 3, but you cannot tell me that they are better than Tesla. Nobody but Tesla knows this for a fact.

 

[cwerdna]

Like I said, forums are are not a definite indicator of anything. I'm not making excuses for Tesla, just stating my experiences and others I know(who actually own the car).

Obviously you have 0 experience in engineering and racing, or you would know that more power almost always results in less reliability. Simple physics.

Is this an example of the proactive warranty replacements made by Nissan you are talking about? Lol. Just face it, the current auto manufacturers have no interest in customer service. Once you buy it, and have problems, anything can happen. Note that multiple people had problems with the repairs of the same problem, so no, not an isolated incident.


http://www.mynissanleaf.com/viewtopic.php?f=30&t=15372

It's a given that Japanese automakers have better reliability than the Bailout 3, but you cannot tell me that they are better than Tesla. Nobody but Tesla knows this for a fact.

Wow, thanks for the personal attacks. My major in college was computer science and was in my college's school of engineering. As for racing, I'll admit my racing experience is limited to some runs at the drag strip w/my previous cars.

There are PLENTY of vehicles w/higher horsepower and torque ratings which have better reliability than wimpy ones. It is NOT a given that higher horsepower always == lower reliability, given proper engineering. There are cars w/modest horsepower and/or torque ratings which are unreliable.

Sure, there have been some instances of Nissan dealers doing a crappy job of repair attempts and this is true of all automakers. I will say that Nissan responded very poorly for a long time to the Phoenix and hot climate battery degradation. They STILL haven't given Leaf owners a battery pack price and instead came out w/a $100/mo battery rental program, which is unsatisfying to many (and has many other negative implications).

As for Tesla having better reliability than Japanese automakers? I don't see any indication of that (at least not better than Toyota and Honda; Nissan is hit/miss) and we have no long term stats.

From earlier posts at http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=338&hilit=350z&start=390, it seems like you jumping to conclusions about the backgrounds of others, like myself and again, making excuses.

Your posts seem contradict themselves:

This is a non-issue. I have driven many Model S cars including my own, and some have the hum, but it's not that noticeable. After 13k miles in my car, a few thousand in others, and having been in the auto repair business all my life, I can say with confidence that the Model S will last much longer than any other car on this planet, and need fewer repairs.

Yet, from your latest post you state "that more power almost always results in less reliability. Simple physics." and an earlier post:

High performance cars have a higher drivetrain failure rate than econoboxes. Since the Model S motor puts out about 4X the power of the leaf and prius, I'm not really surprised there has been some replacements. It seems like most of the replacements are for a little bit of noise that the inverter makes. Please show me any 416hp powerplant that is silent if you disagree.

You can't have it both ways.

In terms of units on the road, there aren't that many mass market passenger car class vehicles on US roads w/even 400 hp and not that many "light truck" class vehicles w/that much power either.

Tony chimed in with this:

Rav4 EV makes 156 horsepower... and the motors go out. Plus, it's built to allegedly handle the full 416hp.

 

[yblaser]

Guys, can you take this discussion outside (this thread)!

 

[Dianne]

Mine hums.
Yesterday it was doing an Aerosmith tune ...

No seriously... mine hums and has a mild light clattering sound that I can hear when it's close to a wall or barrier like center divider.
I can really hear it when I accelerate at my storage unit because there are garages/walls both sides so it reverbates.... but it doesn't bother me and my car's doing fine.

 

[qwk]

Like I said, forums are are not a definite indicator of anything. I'm not making excuses for Tesla, just stating my experiences and others I know(who actually own the car).

Obviously you have 0 experience in engineering and racing, or you would know that more power almost always results in less reliability. Simple physics.

Is this an example of the proactive warranty replacements made by Nissan you are talking about? Lol. Just face it, the current auto manufacturers have no interest in customer service. Once you buy it, and have problems, anything can happen. Note that multiple people had problems with the repairs of the same problem, so no, not an isolated incident.


http://www.mynissanleaf.com/viewtopic.php?f=30&t=15372

It's a given that Japanese automakers have better reliability than the Bailout 3, but you cannot tell me that they are better than Tesla. Nobody but Tesla knows this for a fact.

Wow, thanks for the personal attacks. My major in college was computer science and was in my college's school of engineering. As for racing, I'll admit my racing experience is limited to some runs at the drag strip w/my previous cars.

There are PLENTY of vehicles w/higher horsepower and torque ratings which have better reliability than wimpy ones. It is NOT a given that higher horsepower always == lower reliability, given proper engineering. There are cars w/modest horsepower and/or torque ratings which are unreliable.

Sure, there have been some instances of Nissan dealers doing a crappy job of repair attempts and this is true of all automakers. I will say that Nissan responded very poorly for a long time to the Phoenix and hot climate battery degradation. They STILL haven't given Leaf owners a battery pack price and instead came out w/a $100/mo battery rental program, which is unsatisfying to many (and has many other negative implications).

As for Tesla having better reliability than Japanese automakers? I don't see any indication of that (at least not better than Toyota and Honda; Nissan is hit/miss) and we have no long term stats.

From earlier posts at http://www.myrav4ev.com/forum/viewtopic.php?f=8&t=338&hilit=350z&start=390, it seems like you jumping to conclusions about the backgrounds of others, like myself and again, making excuses.

Your posts seem contradict themselves:

This is a non-issue. I have driven many Model S cars including my own, and some have the hum, but it's not that noticeable. After 13k miles in my car, a few thousand in others, and having been in the auto repair business all my life, I can say with confidence that the Model S will last much longer than any other car on this planet, and need fewer repairs.

Yet, from your latest post you state "that more power almost always results in less reliability. Simple physics." and an earlier post:

High performance cars have a higher drivetrain failure rate than econoboxes. Since the Model S motor puts out about 4X the power of the leaf and prius, I'm not really surprised there has been some replacements. It seems like most of the replacements are for a little bit of noise that the inverter makes. Please show me any 416hp powerplant that is silent if you disagree.

You can't have it both ways.

In terms of units on the road, there aren't that many mass market passenger car class vehicles on US roads w/even 400 hp and not that many "light truck" class vehicles w/that much power either.

Tony chimed in with this:

Rav4 EV makes 156 horsepower... and the motors go out. Plus, it's built to allegedly handle the full 416hp.

I guess we will just have to agree to disagree.

Notice I said almost always on the reliability. Also, of the drive units that Tesla replaced, how many actually failed? A slight noise out of an AC motor is definitely not a failure. It's normal. Just because Tesla has great customer service, and replaces parts as a goodwill gesture, that doesn't count as failures.

If the leaf has such great reliability, then why did you lease one? A lease is almost always a money loser vs. buying. Is it the fear of battery degredation? :lol: So much for Japanese automakers building reliable EV's

 

[miimura]

If the leaf has such great reliability, then why did you lease one? A lease is almost always a money loser vs. buying. Is it the fear of battery degredation? :lol: So much for Japanese automakers building reliable EV's

There are a number of reasons to lease an EV that don't have to do with reliability or "battery risk". If your tax situation is such that you can't take the tax deduction yourself, Nissan essentially gives it to you in the lease as a cap reduction. Also, in the case of the RAV4 EV, the money factor is nearly zero, so you're not losing money in interest like you would with a normal car lease. I don't know what money factor Nissan uses. IIRC, the RAV4 lease only costs about $32 in interest over the 3 year term. To me, that is nearly zero.

 

[Khaihon]

Mine hums.
Yesterday it was doing an Aerosmith tune ...

No seriously... mine hums and has a mild light clattering sound that I can hear when it's close to a wall or barrier like center divider.
I can really hear it when I accelerate at my storage unit because there are garages/walls both sides so it reverbates.... but it doesn't bother me and my car's doing fine.

Hi Dianne,

Does your hum sound similar to this by chance?

http://www.youtube.com/watch?v=dIOWNmd8F-o

Mine definitely makes a hum that is very audible when driving near a wall or alleyway.

 

[TonyWilliams]

Mine hums.
Yesterday it was doing an Aerosmith tune ...

No seriously... mine hums and has a mild light clattering sound that I can hear when it's close to a wall or barrier like center divider.
I can really hear it when I accelerate at my storage unit because there are garages/walls both sides so it reverbates.... but it doesn't bother me and my car's doing fine.

Hi Dianne,

Does your hum sound similar to this by chance?

http://www.youtube.com/watch?v=dIOWNmd8F-o

Mine definitely makes a hum that is very audible when driving near a wall or alleyway.

Great recording that captures the sound well.

 

[Dianne]

If you're talking VPNS, no. I disabled mine.
If you're talking light whine with accelerator clatter, yes. I can try to capture it on sound byte.

 

[spkobay]

Finally... My RAV is now in the shop having the motor/gearbox assembly replaced. My issue was diagnosed in October and we have been waiting all of this time for the assembly. Hopefully in a day or two I'll have a significantly quieter car.

I'm still driving my RAV while waiting for the replacement. I did open the case with Toyota 800 yesterday and received a call earlier today. No action yet, but they wanted to advise me that my case has been handed to a specialist that deals with these type of issues (whatever that means). Anyway, the person to which it was assigned is scheduled out until tomorrow, but wanted to update me since they had promised a call back within a day.

So... I wait for tomorrow and see what a new day brings.

Today I am essentially at one month since opening the case with Toyota. I've had a couple conversations with the rep - they trend in the direction of "We're blaming Tesla, we have to wait, no update but will let you know when we do.".

This is now 3 MONTHS since the hum was diagnosed at my dealer, was agreed that the motor/gearbox needed to be replaced and the part was ordered.

 

[cwerdna]

Notice I said almost always on the reliability. Also, of the drive units that Tesla replaced, how many actually failed? A slight noise out of an AC motor is definitely not a failure. It's normal. Just because Tesla has great customer service, and replaces parts as a goodwill gesture, that doesn't count as failures.

If the leaf has such great reliability, then why did you lease one? A lease is almost always a money loser vs. buying. Is it the fear of battery degredation? :lol: So much for Japanese automakers building reliable EV's

There are a number of reasons to lease an EV that don't have to do with reliability or "battery risk". If your tax situation is such that you can't take the tax deduction yourself, Nissan essentially gives it to you in the lease as a cap reduction. Also, in the case of the RAV4 EV, the money factor is nearly zero, so you're not losing money in interest like you would with a normal car lease. I don't know what money factor Nissan uses. IIRC, the RAV4 lease only costs about $32 in interest over the 3 year term. To me, that is nearly zero.

Sigh....

The excessive noise coming out out of the motor/gearbox wasn't like that when new and when it rose to the point of excessive, where Tesla or Toyota would replace, that's not "normal". It still required at least 1 shop visit, some downtime and replacement of a very expensive part. I'd hate to have to get that replaced out of warranty.

qwk, as for your last jab, sigh... you and your attitude. Battery degradation is unrelated to reliability. miimura's correct, there are numerous reasons to lease instead of buy, even though I'm not a fan of leasing.

And, I'd wager there have been far more Model S and Rav4 EV packs replaced due to failure than Leaf packs, despite there being 4x the # of Leafs on the road worldwide.

I don't always have time to write a book explaining my reasons but I've explained some of them before elsewhere. I live in a house my parents own (but they don't live at this house). I charge for free at work. My commute is well within the range of my Leaf. However, both could change (job, where I live (parents will eventually move back to this house), etc.) and I may not be living at or working at a place where I can charge, hence a 2 year lease.

And, I certainly didn't want to buy a Leaf as its resale value is crappy. If we see evolutionary improvements in EV range and cost, how's a 75 mile (EPA rated range) EV w/a degraded battery going to stack up to whatever exists in 2 or 3 years? IMHO, Nissan's residual is inflated and I can do better buying a used '13 Leaf for less than the residual in the end (if I wanted to) or I'd lease some other EV/PHEV. If the residual is too low, I win, I can buy it out for cheap or turn around and sell it for a profit.

 

[spkobay]

Got my RAV back. Haven't had the opportunity completely run it through, but all seems significantly improved.

 

[cwerdna]

I haven't been following Edmunds' Tesla Model S long-term review but the chatter at http://www.teslamotorsclub.com/showthread.php/14216-Edmunds-Model-S-Long-Term-Test/page12?p=579780&viewfull=1#post579780 about needing a 2nd powertrain in 19K miles made me search for references to the first.

http://www.edmunds.com/tesla/model-s/2013/long-term-road-test/2013-tesla-model-s-ominous-noise-fixed.html was the first replacement in November 2013 @ ~10K miles. http://www.edmunds.com/tesla/model-s/2013/long-term-road-test/2013-tesla-model-s-ominous-noise.html has videos of the noise they refer to.

It'll be interesting to hear the details about the 2nd...

Currently, the latest entry I see at http://www.edmunds.com/tesla/model-s/2013/long-term-road-test/ is from Feb 11, 2014 @ 17,803 miles.

edit: Update on the above. These are all one and the same incident.
http://www.edmunds.com/tesla/model-s/2013/long-term-road-test/2013-tesla-model-s-stuck-on-the-freeway.html
http://www.edmunds.com/tesla/model-s/2013/long-term-road-test/2013-tesla-model-s-is-the-third-drive-unit-the-charm.html

Drive unit was replaced (a 2nd time) along w/HV battery pack and 12 volt battery.