What's up with Edmunds and drive units?

What's up with Edmunds and drive units?

They're on their fourth drive unit in 30k miles. Not good. | 8 juillet 2014

They have been rather brutal on their car, although they actually paid for their car unlike most outlets/magazines. I'm surprised Tesla didn't void the warranty, although the press would have a field day if they did.

negarholger | 8 juillet 2014

Don't you have to pull a fuse to do that?

I see that actually as positive... now is the time to debug the drive train and learn your lessons. Model S in next 10 years will sell half to one million cars... so far they have only delivered 4-8% of that, so the bulk is still ahead of us. Add MX and it is even less. | 8 juillet 2014

I should also point out that I feel the Edmunds reporting is quite fair and seems unbiased. Note that the drive issues never left the car stranded and were replaced due to a minor noise heard from the drive unit. While a drive unit replacement is not unheard of, it seems quite rare based on those who've talked about it on the forums.

Rocky_H | 8 juillet 2014

@Kleist, nah, don't have to pull a fuse. You can turn traction control off in the settings of the touchscreen, and it will let you do that. We had a lot of rain one day, so as I was about to leave work, I turned traction control off and did a couple of fun power slide spins in the wet parking lot. (Huge, very empty parking lot, by the way)

Thomas N. | 8 juillet 2014

TeslaTap - that picture might explain ONE drive unit. The other three?

Maybe they continued driving it that way.

AmpedRealtor | 8 juillet 2014

Tesla has issues with its drive units, and as an owner, I am concerned.

Someone who uses his Model S for commercial purposes, and who was not able to purchase an extended warranty, was charged $15,000 for an out-of-warranty drive unit replacement. This person started a thread about it a couple of months ago.

I have personally received two drive unit replacements in the 11 months and 11,000 miles that I've driven my car. Both replacements were due to noise, but were otherwise functioning normally. The noise was not something that could be overlooked, it was quite noticeable and louder than the stereo. Local Phoenix service told me that there was a period of time last year when they were doing "several drive units per week", and that's with fewer than 500 Model S cars in the state.

The same service advisor also told me that some modifications and changes were made to the drive unit in order to address the droning noise issue, but he also said they continue to receive complaints. There is definitely something going on here.

Kimscar | 8 juillet 2014

@AmpedRealter. Following the forum for more than a year that's why I bought the extra 4 years of warranty. I hope these issues are close to being worked out but just in case. amped did you ever record the sound in your car of the drive train noise. It would be good to have a database of sounds if the owners were capable of making a good recording. I hope problem doesn't happen to me but if it does I will record it.

Also taking traction control off and spinning the rear wheels should be less stress on the drive train.

DZ1DRW | 8 juillet 2014

Had my drive unit replaced at about 10,000 miles. Had a "clunk" sound going back and forth between power and regen. Seemed to me like too much backlash. They replaced it and now is like "as delivered" in late Jan '14.

AmpedRealtor | 8 juillet 2014

Quickly... The drive unit is one of Tesla's supposed core competencies. It is entirely of Tesla's design and consists of a liquid cooled motor, inverter, gear reducer and other goodies. While modular and relatively straightforward to replace, functionally the drive unit is the equivalent of an ICE engine. How many ICE vehicles have you heard about requiring four engine replacements in the first year? Or even two, as is my case? As an owner of much less expensive vehicles, the possibility of experiencing multiple engine replacements in a brand new car was unthinkable until I experienced it twice with my Model S.

According to this TMC poll, drive unit problems are afflicting over 50% of respondents. While that's hardly scientific, it tends to support the anecdotal evidence that these are not simply isolated incidents.

aed98033 | 8 juillet 2014

Our 2013 Model S has over 28K miles on it in the 17 months of ownership. No noise from the drive train. Still drives just as well as the day it was delivered. | 8 juillet 2014

@Thomas N. - It's clear others have had problems. I do think "4" is misleading as Edmunds only got three units. One was a replacement that was defective from the factory and was replaced before ever giving it back the Edmunds. Most non-Tesla service shops hide the fact when a replacement is bad, so give some credit to Tesla for at least telling the truth. That said, even one replacement is not great.

It does seem most (but not all) of these are being replaced because of noise and not due to failure. I suspect most other car companies would have just said "This is normal" and refuse to replace it. I know I've been given the "This is normal" line at more than one non-Tesla service shop with luxury ICE cars. | 8 juillet 2014


Perhaps a deep breath is in order. :)

One thing to bear in mind is that the drive unit is not a something you can repair in the field. Even if there is some small component out of whack, the whole unit gets pulled and refurbished at the factory--this is the norm for high-tech gear--very rarely do you do component-level repairs in the field, you swap a board, module, interface, etc, and have the factory diagnose, analyze and repair.

ICE engines are not designed this way--you can replace pretty every component in the field--oil pumps, fuel injectors, timing chains, thermostats, water pumps, whatever, so the comparison is not fair as the design and servicing philosophy is different.

Its also useful to bear in mind that the noise, as irritating as it is, is not leaving cars stranded--the drive units are still working fine, no loss of acceleration, no increased power consumption, etc, so it might be some odd-ball secondary issue that has nothing to do with the engineering goodness of the drive unit.


callisto | 8 juillet 2014

I had the "clunk" coming from the drive unit when moving between acceleration and regen at very low speeds in my 7 month old S P85+. The Houston SC assured me that it was normal and typical. Last week in the middle of downtown Houston during rush hour with three business associates in the car, the drive unit gave out and the car just wouldn't go. Roadside service reacted incredibly well and they had the car repaired and back to me in less than 24 hours. The reaction and response when the drive unit went out was great but I KNEW that the "clunk" sound just couldn't be normal and that anything taking enough punishment to make that much noise would have to fail eventually. I wrote the service and engineering department earlier this week and restated my concern about the clunk and that I felt it was related to the drive unit failure.

TeslaLandShark | 8 juillet 2014

@omarsultan - I'm with you on the replacement versus repair, it makes sense. The issue that I have is that you will get charged $15K once the car is out of warranty. It could be some trivial thing that is easily repaired when the drive unit is sent back to the factory. It shouldn't cost the owner $15K because its more convenient for Tesla to replace the whole unit rather than repair it in the field.

AmpedRealtor | 8 juillet 2014

TeslaLandShark makes an excellent point. | 8 juillet 2014

I would think, at that point, there would be a credit for the returned "core". I dunno, this is all conjecture--I think the only data point we have is the one livery dude who ended up paying the $15K--I am not sure you can extrapolate that into general policy--I am guessing Tesla probably does not have anything in place yet.

O | 8 juillet 2014

Following up on my own comment, only Tesla knows if the drive unit noise thing is some short term problem component issue like the 12V battery that will eventually flush out of the supply chain or if there is some fundamental engineering flaw. Either way, based on various bits of info out there, they seem to have an audio profile of the issue and have given it a name ("milling sound"), so I would assume they know what the problem is and have executed an on-the-fly fix. Said fix should work its way through the population of Teslas in the wild as the fix is applied under warranty or ESA if the problem manifests itself.

If we go back to the high-tech support example, what I would not mind paying for the ability to buy an on-going support contact for my Tesla that covers parts and service, much like I can for IT gear.


Sudre_ | 8 juillet 2014

Very similar to the battery replacement where Tesla takes the core and does not give a reimbursement for it.

I am not sure how it works but I know in MO with an ICE you can request to keep the bad part since it's yours to start with. There was a time when dealers where replacing parts and not ACTUALLY replacing parts.

Tesla is going to have some serious lawsuits on their hands if they try this after selling a few million Model Es. If you are paying out of pocket to have a part re[laced, you still own the broken part.

Battery backs can have an opposite effect since they can't be dumped. You can get charged a disposal fee. I am pretty sure I could sell a Tesla battery pack on ebay for at least a dollar (+ shipping and handling) functioning or not.

It will be interesting to see how this plays out in the long run.

tramline | 8 juillet 2014

...are Edmunds Tesla shareholders or something, replacing three drive units on a $100,000 car barely 6 months old along with other issues to most people would be considered a pile of lemon c*** and yet as an independent car review body they seem very reluctant to come down hard on Tesla.... makes me wonder...

AmpedUP | 8 juillet 2014

This, along with the 12 volt issue, is why I am sticking to my very late February 2015 delivery date. BTW, with patents no longer an issue and as some of the early super high mileage S-40, S-60 vehicles start to run out of warranty (including battery), I wonder if a cottage industry might be born here...replacing drive units, coolant pumps, etc with non-Tesla parts.

Iowa92x | 8 juillet 2014

Do we know what is causing the noise or failure of the drive units? Could be multiple causes for various owners, but was curious if a pattern has been established.

tramline | 8 juillet 2014

There have been reports of the motor mounts being a possible contributing factor...

NO2PTRL | 8 juillet 2014

I bought my P85 because it goes fast and corners on a rail.
I expect this car to hold up as well as my Porsche Turbo or my Mercedes SL55 of which I drove both very hard.

Why own this car unless you can drive it hard.

Being new technology, I can't imagine not buying the extended warranty.

4000 miles and counting, and everything is working perfectly.

I push my P85 every time I take it out!

negarholger | 8 juillet 2014

@tramline - it is a resonance in the drive train and it is loudest around 70-72 miles per hour... the most favorite speed on US highways. To dampen the resonance yes, motor mounts are important. To excite the resonance there can be many potential sources like imbalanced rear tires to a noisy bearing.
Resonances are not unusual in a newly designed mechanical system, Tesla just has to work through it. In an ICE you would never hear that as the engine noise drowns everything out. You only hear it just because the Tesla is so quiet. Challenge of a new way to do things...

Captain_Zap | 8 juillet 2014

Some residents of some states can't get the extended warranty yet, it is still being worked on, AFAIK.

AndyO | 9 juillet 2014

There's also the accelerate to decelerate clunk. I've read about several of those. Some precede a total failure (at least in one case I read). I had my drive unit replaced for that last week. Also got a new side motor mount.

I hope Tesla works out the issues with the State of Fla for the extended warranty before mine runs out. I was counting on that.

johncrab | 9 juillet 2014

It sounds like they are not performing drivability evaluation but test to destruction evaluation.

Thomas N. | 9 juillet 2014

I just read the comments over there. Bunch of armchair quarterbacks. At least the armchair quarterbacks over here understand Tesla.

This whole 10K mile, 20K mile, 30K mile interval thing is complete baloney in my opinion. It happens when it happens - or it doesn't.

I agree there is a problem, but I'm not certain it's as pervasive as made out to be online.

Where is m5ashby? I think he's got to be up to 80K+ miles on a pretty early-production vehicle. He surely should be on his 7th or 8th drive unit. I'm not even certain if he's ever had one replaced. It would be interesting to hear.

I'm still under 10K miles after a year. No problems. Maybe I'm the outlier. Nah. There's got to be thousands upon thousands of owners like me out there.

Now if I need a replacement at 11K miles I'm going to raise my eyebrows a little.

I take really good care of my motor. No burnouts, low miles, glass-smooth roads. Lots of 0-60 starts but they shouldn't be too hard on an electric motor. What I'm not crazy about is getting a drive unit replacement that is a refurbished motor. It could be from some car with 40K miles, or it could be from the Edmunds car. I'm sure they bring them up to "factory specs and tolerances" but now your motor is gone and you've got whatever they give you.

How does that work with mileage? Are these refurbished motors zero'd out? If you get an all-new engine dropped into your car you restart the miles on it. Just new pistons? Then you've still got 104K on the engine.

Then again, I don't want to be without my car for a month while they sort out my drive unit. New would be nice but that's unreasonable financially for Tesla.

So far no problems for me. (knock on Obeche matte wood).

My5bAby | 9 juillet 2014

@ Thomas N

LOL :-)

I'm up to 87K, I did have one drive unit change, roughly around 40K, It has been wonderful ever since.

LEvans | 9 juillet 2014

In 6-8 years a Model S will be worth about $30K. When that happens a $30K car should not be in need of a $15K repair as if that happens often enough and the word gets around no one in their right mind would want to own a Model S out of warranty.

I know Tesla has stated they never want to make money out of repairs because their point is that the vehicle failed because they did not built it properly. The fact that they seemed to have charged some poor soul $15K for a drive unit replacement makes me question that. At the least they should have covered half the cost of the repair as a good-will gesture, especially given the fact that they ostensibly got to keep the original drivetrain to refurbish and refit.

If these vehicles get known for $15K repairs out of warranty they'll hardly have any meaningful residual value as few would want to touch them used out of warranty and then we will all end up paying for it with a higher cost of ownership. IMHO Tesla needs to get some of these out of warranty repair costs to more reasonable levels.

arreefdiver | 9 juillet 2014

As an owner who has both the drone/hum problem persisting even after two drive unit changes, and the low speed clunk now, I can relate to others experiencing the same who worry what implications this may have down the line when we are out of warranty, especially since as a Florida owner I cannot purchase an extended warranty. I have let Tesla know about the problems and basically accept their statements that it is within normal specs, since these problems don't really bother me much. However, if my drive train fails later and these symptoms were early signs of a faulty, destined-to-fail drive train, will they still want me to shell out 15k to replace when it is out of warranty? I always intended to keep the car a long time but this is definitely a concern for me. | 9 juillet 2014

Let's look at a large competitor - Porsche to put a little bit of perspective on this. They produce the very nice 911 GT3, a $120-160K sports car. Every single car produced has to have the engine replaced due to high risk the engine catches on fire. I suspect the engine replacement is a lot more than $15K.

After some time Porsche figured out the problem and has a solution.

Tesla is replacing motors because they a) die (quite rare), b) make more noise that can be heard in a very quiet car (sometimes). I'm sure Tesla has or is solving the issue even if it is rare. Should you worry about it? Some will most won't. It seems like they are mostly replacing them as customer goodwill rather than something is failing.

Captain_Zap | 9 juillet 2014


Our Porsche had to have engines replaced, on average, every two years. That was just driving it on weekends with two or three 20 to 40 minute sessions a day, about 10 times a year.
That isn't even counting major repairs.

Red Sage ca us | 9 juillet 2014

Here is what I told them in the comments:

I'd like to thank everyone on the Edmunds staff for covering the Tesla Model S so thoroughly. You guys have been great. I like that you have been fair and honest with us about the car. I am sorry you have had problems, but it is very reassuring to know they have been handled so well, and to your satisfaction.

Regarding the annual service... Someone on the Tesla Motors forums noted that there's a bit more to it than what is listed in public documentation. The Tesla Service Center does more than just a cursory inspection of your car -- what they did while replacing your drive unit. They do a complete inspection of the vehicle, stem to stern, effectively taking the entire car apart, physically checking every single nut, bolt, pin, and panel, replace anything and everything that might be even the slightest bit out of whack, then put the car back together again.

So, if you intend to keep the car -- get the annual service done. If you intend to sell the car -- get the annual service done. It really is worth every dime, and then some.

Thomas N. | 9 juillet 2014


My sincere apologies for the butchering of your username. There's something about that Capital A in the middle that throws me off every time!

One drive unit in almost 90,000 miles? I was thinking not too shabby but then I realized that you really shouldn't have any replaced. Period.

Tesla will get this right. They've got brilliant people on staff. The best of the best engineers. If they replaced my drive unit tomorrow I'd smile and keep driving.

I think I'm finally going to pony up the $4K to get this thing covered until 2021 however!

AmpedRealtor | 9 juillet 2014

+1 Thomas N.

I recommend owners buy the extended warranty if they can. I bought mine early and it was only $2,500 before the price increase last summer. It is transferrable to a subsequent buyer. I feel that having an 8 year 100,000 mile warranty is going to add some serious resale value to this car if some of these issues persist.

The other thing to keep in mind is that other car makers usually have a 100,000 mile drivetrain/powertrain warranty which would cover an engine and/or transmission replacement. Tesla has no separate drivetrain warranty, so by default its drivetrain is only warranted for 4 years or 50,000 miles unless you pick up the extended warranty.

In my opinion, Tesla should add a separate and robust powertrain warranty.

Tâm | 9 juillet 2014

Would someone please explain what is in a "drive unit" that costs $15,000? Is there gold or diamond that I don't know about?

Isn't it just a gear?

If so, Tesla Roadster had repeated failures with initial two-gear transmission.

It learned the lesson ditched the transmission and settled with a single-gear-box design which is also what we now have in Model S.

Apparently, it has always been a challenge for a transmission or gear box that has to put up with the punishment of high torque and high RPM electric motors.

Thomas N. | 9 juillet 2014

It's the motor, bro.

L8RSK8R | 9 juillet 2014

Good thread, I'd no idea of these issues. I'm passing for now, on buying a Tesla. Mine would be out of warranty in 18 months or less. Having to spend $15k for a motor, would be a huge setback to my business. | 9 juillet 2014

I am at 31k & have not experienced these problems. I bought the extended warranty, service contract, and wheel insurance (no longer available) when I took delivery on my SP. No regrets for those purchases. Very nice discussion in this thread.

LEvans | 9 juillet 2014

++1 on getting that 8 year extended warranty. I wouldn't buy one without it.

This would be a big deal and add significant resale value to the car if you decide to buy another Tesla and sell your current Tesla.

Having that extended warranty for 8 years will allow you to sell a Tesla as a CPO car for all practical purposes after you get it detailed.

On the flip side I think people who don't have the extended warranty are going to have a harder time selling this car out of warranty.

Tâm | 9 juillet 2014

Here's what I found in an expired help wanted ad:

Tesla is looking for a highly motivated Senior Controls Engineer to develop new automation equipment and assembly lines for our cutting edge Drive Units (Motor, Gearbox and Inverter assembly)

No wonder why it costs so much. It's a cost for 3.

1) Motor
2) Gearbox
3) Inverter

I doubt it's a problem of motor nor inverter.

Most likely it's a Gearbox problem that carries through since the early day of Tesla Roadster prematurely worn out transmission.

As you see the picture below, I think the motor is on the left which is soldered into the central Gearbox. The Gearbox is attached to the Inverter on the right.

It looks like it's much easier, but costly, to just replace the whole assembly of the 3 components.

LEvans | 9 juillet 2014

@Tam: Great find! Thanks for sharing.

I think it would really help if they could try and separate the 3 components for the sake of those who will eventually own this car 6-8 years out. I bet many would not want to find out one day that they need a new drive unit and it costs half as much or more than the value of the car at that time...

Anecdotal evidence of exotic cars requiring new engines notwithstanding it seems this issue is more prevalent than what most would consider to be acceptable. I'm sure Tesla will figure out a more robust way to implement the drive unit but IMHO it is not ideal to have a $15,000 part that could fail in the car.

windex | 9 juillet 2014

The primary problem is that Tesla is still learning. They send drive units to the factory for repair to study failures.

Eventually they will likely offload some repairs to the field at service centers, but they aren't doing that now which is part of the reason everything is replace and not repair.

The 15k cost is for a new replacement of a hand assembled unit. It's actually reasonable when you consider the materials and labor required to push a finished product by hand.

Over time this inefficiency will likely improve.

Red Sage ca us | 10 juillet 2014

fordson1, a long standing Naysayer among those commenting on the Edmunds long term test for Tesla Model S told me, "You sound as though you think a car is made up of Lego blocks and you just pop them apart and them pop them back together as many times as you want."

So I answered:

I would hope that I sound like a Tesla Enthusiast who believes Tesla Motors is doing their absolute best to preserve and maintain the reputation of the firm.

I certainly hope I sound like someone who would appreciate the efforts of Tesla Motors to protect the resale value of their vehicles.

I absolutely hope that I sound like a reasonable individual who believes Tesla Motors Technicians are consummate professionals who are well trained to properly inspect a fully modular electric vehicle, making essential updates and inspections a painless endeavor.

I undoubtedly hope that others would be moved to enjoy having a car that was 'like new' when it leaves a Tesla Service Center, as noted in the above article.

I do not yet own a Tesla Motors product myself, but I really hope to do so someday, and I am thoroughly impressed by their Service, as have been numerous owners who have attested to such, and now expect that I would be equally rewarded for my purchasing decision by having any and all current and potential issues handled pro-actively.

I don't particularly care what you find 'quite simply unbelievable', though I hope you understand the sentiment that I believe my being labeled a Tesla Motors Certified Apologist Fanboy is an absolute honor.

Pungoteague_Dave | 10 juillet 2014

My first drive assembly was replaced at around 11k miles. It was explained to me at the time as an inverter issue. There is no way to separate the motor, inverter, and gear transfer unit outside of the factory. The replacement involves dropping the entire rear subframe/suspension and therefore includes a full alignment. My car was picked up today by Tesla at my home (I am in Spain for a couple months hiking el Camino de Santiago). It will be evaluated and I suspect will be receiving its third drive unit. We do not drive the car hard. Clearly this is a fairly pervasive design issue affecting a significant percentage of cars. Every car in my area has had at least one drive unit replaced, now that m5bAby has disclosed his replacement.

I would definitely not purchase this car without the extended warranty. My warranty work so far now exceeds original purchase price.

@Red Sage, you are incorrect on the annual process. Tesla does not take the car apart during the annual service. They inspect and check visible items, but do not remove body panels and cannot see the vast majority of the car's bolts. For example, the inspection would not have found the loose structural bumper bolts that were never tightened during initial assembly because they were behind the plastic bumper cover. Because this was discovered during the hitch installation on my car, Tesla did take my car for a week to tear it down and check all bolts and nuts. However, this is not done routinely on all Teslas.

Rocky_H | 10 juillet 2014

That seemed like a huge exaggeration of the annual inspection. From the fact that it can be done at your house by a service ranger would make it very unlikely that they would take much of the car apart.

basf_audio | 10 juillet 2014

I'm on my 5th drive train right at 12,000 miles. Tesla is doing a buyback for me and I'm okay with that, even though everything that I've had serviced is fixed and working properly. All noise related issues, not reliability or safely concerns, all under warranty.

carlk | 10 juillet 2014

@NO2PTRL Porsche of course is race hardened but you should know how reliable early Porsche are. Or for that matter even many modern day super cars that are pushing the envelop. Even Porsche will not honor the warranty if it found out from the log that the car has red-lined too many time.

Thomas N. | 10 juillet 2014

Oh basf_audio - that's terrible. 5 of them? There must be some other intervening part that causes these multiple failures. How come the Edmunds car is on their fourth? How are you on your fifth? How come I'm on my first and it's perfect? There's some system somewhere that interferes and causes this with certain cars.

Just bad luck? Doubtful.

Red Sage - Your heart is in the right place but unfortunately you really exaggerated the annual and thus probably lost a lot of credibility for Tesla fanboys over on that Edmunds site. I've read that stuff by fordson1 and he's just an old angry person that likes to fight. I noticed he's in almost every long term thread over there so at least he's not on a mission to ruin Tesla. He's just on a mission.