Edmunds Model S Long-Term Test

[Red Sage]

I see the word 'failure' is used a lot in this thread. Perhaps the definition of the word is different for most of you, than it is for me. I would think an outright failure of the Tesla Model S drive unit would involve leaking fluids, broken pieces strewn about on the ground behind the car, and absolutely no warning.

I had a trans-axle failure in my 1990 Honda Accord EX Coupe, which I bought new. It died before I reached 40,000 miles. Completely immobile. Leaking fluid. Dead of night. Flatbed truck. Taken to a Dealership. Replaced under warranty. I was fine with that. If the car hadn't been subsequently stolen and destroyed when it was around 75,000 miles, I would probably still have it. Loved that car.

The worst situation that Edmunds had with their car was that someone was driving on the freeway, received a warning that they should stop the car, they made it halfway down an offramp, and stopped on the shoulder. OK, fine... We'll call that one a failure.

But a proactive replacement because something 'just doesn't sound quite right' is not what I think qualifies as a failure. It is a removal and replacement of a modular component of the car as a preventative measure. Heck, changing an air filter, oil filter, or brake pads is the same thing (yes, that is hyperbole, don't bite my head off). My point really is that in an ICE vehicle there are probably innumerably things that 'don't sound right', but are masked by the general noises the cars make anyway. An EV is so generally quiet, that drivers become intuned to just about any noise, no matter how slight.

Replacements of this sort, done under warranty or in good faith do not concern me in the slightest.

Should a drive unit spontaneously disassemble itself at freeway speeds, blowing out the rear of the vehicle, and causing extreme damage to the vehicle and injuries to driver and passenger, with regularity, ending in a crash... That i would consider a highly dangerous problem, and a complete failure as the result of a faulty design. Have there been any reports of that sort at all regarding the Tesla Model S in the past two years?

This has been Red Sage, Your Friendly Neighborhood Tesla Motors Certified Apologist Fanboy, at your service!

 

[JST]

At this point, I don't think any of us have enough info to know how much concern this should engender. Interesting questions that I have not yet seen answered include:


1. What happens if you don't replace the drive unit? Does the part eventually fail completely?

2. How common an occurrence is this?

3. Are there other contributing factors? Some cars seem to have multiple failures--is there a reason for that?

4. What does it *really* cost to fix, out-of-warranty? To date, Tesla has simply been swapping the drive units and (presumably) sending the old ones back to the factory for diagnosis and remanufacturing. If you needed to do this repair out of warranty, could you do it for less? And what would Tesla charge you?

5. Does the fact that some cars have multiple failures suggest that perhaps the remanufacturing process isn't quite fixing the problem?

 

[NigelM]

Have you missed threads/posts like these? Here are a bunch (nowhere near complete) involving drive unit replacement.

You're conflating a number of issues and assuming they're all the same problem. We don't know they are the same problem and neither do you. We do know that you like to come here regularly and try to gather up as many faults as possible but please at least try to keep it realistic.

I tip my hat to Tesla that they've actively pursued a policy of replacing anything immediately just so they can keep customers happy and take a look at the noisy parts; plus out of ~45k cars built from the ground up for the first time it's not surprising that real world use shows up a few failures.

 

[brianman]

I've had 2 replacements for 3 issues. The first replacement had the noise issue and the "drive unit disengaged when accelerator was pressed"; rebooting the car worked as a temporary workaround to get home, but it was expected that the issue would recur and the unit was replaced. The second replacement was required -- the vehicle reported errors with various systems (stability control and others) and refused engage at all; the vehicle was towed to the service center for the replacement.

That's 2 required replacements in < 25,000 miles.

That's 2 more than I expected when I bought the vehicle based on the "drive unit should last 2 million miles or more" characterization that was thrown around TMC before deliveries began.

 

[William13]

The drive unit replacements are remanufactures of other EARLY Model S drive units. Several units are likely making the rounds. Please remember no one has ever made this type of car before. Other high performance cars have higher failure/repair rates than their pedestrian counterparts.

 

[anticitizen13.7]

The drive unit replacements are remanufactures of other EARLY Model S drive units. Several units are likely making the rounds. Please remember no one has ever made this type of car before. Other high performance cars have higher failure/repair rates than their pedestrian counterparts.

I went back through the Edmunds long-term blog posts, and just to recap:

The first powertrain was replaced because of a warbling sound.

The second powertrain was replaced after it suffered unspecified faults that caused the Model S to shut down.

The third powertrain was replaced due to noise issues.

As far as I can tell, there doesn't seem to be any problem with the mechanical components of the induction motor. The problems appear to arise in the PEM, which has many electronic components.

A re-manufactured powertrain may just have a replacement PEM.

Electronics typically have a "bathtub" shaped failure curve. Units that won't last tend to fail quickly, while those that will last tend to work for a long time. Hopefully Tesla has gathered enough data to both determine the failure points and figure out how to lessen the chance of issues cropping up after delivery.

 

[JRP3]

The noise issues could easily be in the motor and/or gear drive as well, and could be a precursor to eventual mechanical failure.

 

[tenstringer009]

Well, they officially sold the Tesla, and I think they got a good price for it. They must have sold it to a private party since a couple of weeks ago Carmax offered them $79k when it only had 22.5k miles.

 

[cwerdna]

You're conflating a number of issues and assuming they're all the same problem. We don't know they are the same problem and neither do you.

No, I'm not. I was referring to drive unit replacement, whatever the cause/symptom may be.

Noise in virtually every case was just that. Failure == car lost propulsion. In the threads/posts I cited, the drive unit replacements were one of these. No, we unfortunately we don't know the cause in the majority of the situations other than something went wrong within the unit that was replaced and replacing it fixed the problem.

As I said, and others have re-stated. Edmunds had 3 drive unit replacements. 1st for noise, 2nd for failure, 3rd for noise. It's too bad they sold the car so we don't have longer-term data from them and a real price tag, if either noise or total failure happened again outside of warranty, or if the 4th drive unit was the charm.

 

[Sunlight]

As a Tesla watcher (Gen 3 on the horizon) this whole motor issue haunts me. The heart of an EV is the electric drive train and the one component one would assume to be problem free. Also it is a worry that no-one seems to know exactly what the fault(s) is/are.

Why has Tesla not clarified the matter with a detailed statement? - this is so unTesla-like (and counter-productive). Sure Tesla have handled the problems deftly but it has still left Tesla owners and owners-to-be rather nervous.

We can be sure the Tesla must have made this issue a priority and it is disturbing that they don't seemed to have cracked it and newer cars/replaced units still seem to be afflicted. When will a line be drawn under the issue?

I notice from an earlier posting that the motor and final drive are welded together which must make solving this problem that much more difficult. I imagine that it won't be long before the motor and drive are bolted together - maybe they are in the latest models.

Tesla could easily lay the concerns to bed by warranting the power unit for, say, 250k miles or ten years. If the problem has been resolved then this would not be a problem for Tesla but it would remove the current anxiety; show faith in the product and reassure new buyers (who may not be EV fans nor Tesla enthusiasts) who just want a 'reliable auto'.

After all, electric motors/drive units should have a virtually indefinite life! Over to Tesla...........

- - - Updated - - -

Just another quick thought. Most of the anti-EV/Tesla rubbish one reads is so subjective and ill-informed, it is laughable.

But I am surprised the anti-Tesla brigade haven't yet (apparently) homed in on the drive train issue and used it to bash Tesla mercilessly (as that would be more effective and difficult to rebut)

 

[JRP3]

I'm 99.99% sure the motor and drive are not welded together. Because that would be insane.

 

[NigelM]

Noise in virtually every case was just that. Failure == car lost propulsion.

Factually not true. Replacements for noise were for noise, not because the car lost propulsion.

 

[Sunlight]

JRP3 - there was a photo posted on this forum (or the Tesla forum?) - maybe not this thread - showing the chassis and drivetrain installation and the motor and final drive were clearly welded together. There was a fair amount of discussion in this regard.

It may explain why whole units are replaced! I agree it seems a bit mad.........

It MAY have been an early prototype/model which is why I am asking if anyone has a definite answer (not guess...) to the question for the latest models.

 

[yobigd20]

When I asked the SWAG I got was $15K + labor for drive unit replacement out of warranty. I mentally round that up to $25K because I suspect $30K is "high" and $20K is "low".

I'm hopeful (though I haven't asked yet) that a drive unit replacement out-of-warranty at least includes a warranty on that drive unit.

Unlike every other car manufacturer Tesla has no separate powertrain warranty at all. The powertrain is only covered under the original 4 year or 50,000 mile, whichever comes first, new vehicle limited warranty. Once you are out of warranty, if you need a new one it's going to cost $15-$20k (Springfield quoted me this number) and the new one does not come with any warranty.

Fyi, add me to the list of replacements. I'm scheduled to get my drive unit replaced Monday because it is making VERY loud noises.

For me this is similar to the high pitch whine under heavy accel but less pitchy. For me, if I open the rear passenger door and drive around the block this whine is 10x louder which tells me it's pretty loud externally and that from inside the car its muffled. I guess this is expected as the motor/inverter is underneath the car. I've had this sound since around 10k miles and I've complained many times in the past about it. Passengers in my car are even bothered by the sound. It has got louder and louder over time. The car is no longer silent at all. When driving through a closed garage with the windows down it echos off the walls and amplifies the sound. It's quite embarrassing I think because it's always there and unlike the dumb loud AC compressor I can't shut this one off. After several complaints with no resolution, when I was at 49k miles (almost out of warranty), I was worried that I was going to be stuck with this sound forever so I took more audio recordings and sent them in and Tesla analyzed them and said they could hear grinding noises too so now I'm scheduled for a drive unit replacement.

 

[jerry33]

That's why I got the extended warranty.

 

[Zythryn]

JRP3 - there was a photo posted on this forum (or the Tesla forum?) - maybe not this thread - showing the chassis and drivetrain installation and the motor and final drive were clearly welded together. There was a fair amount of discussion in this regard.

It may explain why whole units are replaced! I agree it seems a bit mad.........

It MAY have been an early prototype/model which is why I am asking if anyone has a definite answer (not guess...) to the question for the latest models.

Sunlight, what you saw was the housing that contains both the motor and inverter. Those two devices are not welded together, but are contained in the same housing.

 

[gmontem]

That's why I got the extended warranty.

My S was delivered on November 2012. Back then I convinced myself to get the extended warranty based on two things:

1) Discounting the Roadster, this is Tesla Motors's first car.

2) No one's perfect, including <insert colorful "the onion" praise for Elon Musk here>

 

[William13]

My noise and I think most of the noises were from the PEM/inverter. Tesla is figuring this out. I am just happy I was able to buy the extended warranty. I expect Tesla will continue to do the right thing. I. Expect my car to go >250,000 miles.

I think the problems with the "motor" portion of the drive unit are actually problems with the reduction gearing. Notice the recent post about torque from the Model S. 4000 lbs-ft. Not 400. The gears probably have issues with this.

 

[xhawk101]

Wondering if there r more issues potentially with performance version with me higher forces involved?

 

[JRP3]

JRP3 - there was a photo posted on this forum (or the Tesla forum?) - maybe not this thread - showing the chassis and drivetrain installation and the motor and final drive were clearly welded together. There was a fair amount of discussion in this regard.

What I'm seeing is the motor housing on the left which has one half of the gear case welded to it. Notice the bolts that join the two halves of the gear case and allows it to be split in half. The left end of the motor case has an end cap that is also bolted on. Presumably removing the end cap would allow pulling the motor out of the housing. On the right side is the inverter housing which seems to have a cover with screws holding it on.

- - - Updated - - -

I think the problems with the "motor" portion of the drive unit are actually problems with the reduction gearing. Notice the recent post about torque from the Model S. 4000 lbs-ft. Not 400. The gears probably have issues with this.

That is motor torque times gear reduction. Other vehicles with similar motor torque would have similar final drive torque, or more, depending on the gear reduction.