Sep 16, 2015
kenkamm I've really been loving this car (2013 P85) and the Rockville MD service center has been great. But recently my car started making the milling noise. They made a recording and sent it to Tesla and was told that it was within tolerances.
I'm not satisfied with that response from Tesla. The noise is annoying and taking enjoyment away from ownership. It's getting worse which may be an indication of imminent failure. The noise started suddenly, which is an indication that something has gone wrong. Not all cars have this issue, so the argument that it's within tolerances doesn't hold water with me. It's a known Model S issue and I want Tesla to take ownership of this and fix my car before it ends up leaving me stranded on the side of the road - or worse. My car has about 33,000 miles on it - does Tesla plan to just wait for my warranty to run out and then volunteer to repair it?
I'd like to find out who I can escalate this issue with in MD - anyone know?�
Sep 16, 2015
cgiGuy I just had second drivetrain replacement about a month ago due to this noise. (The first one had milling at low speed, plus droning sound at 70; second was just milling noise.) While getting replaced, I was told by my SC that they have "new" drivetrain designs that are better than the early ones, and the new ones shouldn't develop these noises any more. Keep pushing.�
Sep 16, 2015
Max* You have an 8 year unlimited mile warranty, so no, they're not waiting for you to hit 50k miles.�
Sep 16, 2015
kenkamm That's good. But even with the warranty, I feel the other reasons stated are more than enough reason that this should be addressed.�
Sep 16, 2015
yobigd20 this i don't believe because I just had my DU swapped with a brand new unit (not remanufactured) 6 weeks ago and I have 3k miles on it and it already has started developing the milling noise again.
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it's also worth noting that when this originally started happening to me I went to 3 different service centers before they would swap it. the first two were like 'thats normal' and gave some long spiel explaining that the extreme high power and voltage will cause the components to make that noise over time yadda yadda yadda and it wasn't until i went to a 3rd different service center where they were like 'uh yeah thats not normal and is the milling noise' and have since done 3 DU swaps for this (soon to be 4th DU swap I guess whenever this one gets loud enough to annoy me).�
Sep 16, 2015
kenkamm The problem is, I don't know who to push on. Once the SC folks tell me to go pound sand, I'm stuck. I can't force them to do it, obviously.�
Sep 16, 2015
mknox My second drive unit developed the "clunk" and Tesla said it was within specs. It then developed the milling sound (angry mosquito / buzz saw off in the distance) and Tesla said it was just "cosmetic" but would replace it when parts become available because it is now out of spec. Since then, it's gotten even louder. Still waiting on my replacement.
Perhaps simply bring it up at each service interval. If it is getting worse, it will eventually cross some threshold that Tesla has set.�
Sep 16, 2015
AnOutsider Just posting your tale here alone could lead to a phone call from someone offering to fix it. Good luck. I know it can be frustrating trying to pierce Tesla's communication defenses.�
Sep 16, 2015
PunchIT I think they'll wait for it to get worse and then replace.
I had the humming noise which all my friends complained about. Telsa didn't replace it until it became the clunk noise on load reversal.�
Sep 16, 2015
Zextraterrestrial ...when people ask what that annoying noise is - it is pretty hard to sell them a Tesla!�
Sep 16, 2015
Freudianly I know I will not buy a Tesla as long as this is not definitely fixed. A great reason to buy an electric car is silence. This ruins it.�
Sep 16, 2015
kenkamm In my case the noise is loud enough that my wife and friends have independently noticed it and asked about it. Yet it's "within specs" according to Tesla. When you're not the owner of the car, it doesn't seem as bad. A short test drive does not necessarily reveal how annoying it gets to hear it on a daily basis. It's very evident in certain parts of my commute. Of course, I don't have a Tesla tech in the car with me at those times.�
Sep 16, 2015
hpham007 The noise is an inherent issue with the Tesla drive units. Despite claims by some that tesla has found a solution, I've yet seen evidence of this. Since a DU replacement is inevitable (perhaps multiple replacements), it appears that Tesla will try to get the most mileage out of each unit before replacement to save on costs. The downside is that the owners will have to live with the milling noise.�
Sep 16, 2015
EVenthusiast First thing I thought of was the RAV4 EV, which experienced similar issues (Tesla drivetrain of course).
Is this the noise you're talking about? Is it worse?
(jump to 2:04 to really hear it)�
Sep 16, 2015
vgrinshpun First step in escalation would be to speak with the Service Center foreman (not just service advisor or technician), if this does not work ask foreman for the contact information for the regional service manager, and discuss the issue with him. Good luck.
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There is no *inherent* issue with the Tesla drive units. According to statistical data collected by Consumer Reports the rate of this problem is somewhere between 2 and 3% for older (2012) cars, less than 1% for newer cars.
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May I ask what car do you currently own/drive?�
Sep 16, 2015
Cyclone My car was delivered with the noise. The first time I complained about it, they took a recording and sent it to Engineering. Over the next month, my car developed the clunk and when they checked that, they went ahead and put a remanufactured DU in my car. After three months of driving with the milling noise, it was such a wonderful experience to have the silence in my car. It really is very noticeable. So much so that 5 out of 8 test rides I gave asked about that sound during those three months.�
Sep 16, 2015
kenkamm Mine is a higher-frequency noise best described as a metal-milling sound or perhaps a sound similar to that of a cicada. I can't really tell by listening to your video whether mine is worse or better. My iPhone doesn't pick up the sound very well because it seems to capture low-frequency noise much better than high-frequency noise, so in iPhone recordings I just hear wind and tire noise. In person the noise is easily heard. If I crank my music I can drown it out, but if I listen to an audiobook I can hear it during every little pause.�
Sep 16, 2015
hpham007 I agree; this definitely needs to be escalated. To pay for a 100k car and asked to live with irritating noise is unacceptable.�
Sep 16, 2015
Zextraterrestrial this sounds more like gear whine to me
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true.
The only time I have been sad driving my Tesla is when it was making the 'inverter' noise. It also caused me to try and drive differently so that I'd never be coasting at the low power draw that would produce the sound. Either floor it or put it in neutral and coast.
the whine makes it sound like a bad Karma�
Sep 16, 2015
Beckler Seems like the easiest fix for this would be earplugs.
�
Sep 16, 2015
Freudianly I do not drive a car. I cannot stand the noise. I will buy one when I am absolutely sure it is silent in the long run, and with at least the autonomy of a Model S.�
Sep 16, 2015
AB4EJ Does anyone have experience with what happens eventually if the milling noise occurs and then is never fixed? Does the gearbox eventually overheat and fail, or what?�
Sep 16, 2015
mknox I believe it is an electrical sound, not a mechanical sound. Probably related to high amperage ac current causing a winding or something to vibrate. Tesla tells me it's a "cosmetic" issue, so I think they must agree. They hopefully wouldn't push off my repair if I was in imminent danger of having an outright mechanical failure.
My first drive unit developed a completely different sound. It was a very loud, but low frequency hum that reminded me of standing next to a big power transformer. It only happened when power was applied, and not under re-gen or if I was coasting with the power meter near zero. They replaced that one right away. It never had the "clunk" between power and re-gen that my current unit developed.
I think there have been mechanical failures, but they are very rare compared to this.�
Sep 16, 2015
Lyon FWIW, these issues seem to be limited to vehicles with performance drive units. If you get a regular dual motor unit you should be fine.
Also, I'm on DU 3 at the moment in my late 2012 P85. Only 23,000 miles on the car. So far so good with this one but the receipt they sent me indicated a remanufactured unit so we'll see. They're getting much faster at doing the swap though.�
Sep 16, 2015
apacheguy The milling noise affects base DUs as well.�
Sep 16, 2015
mknox Yep. Mine is a base. Interesting though, Tesla told me that the problem is more aligned with Performance models. They said with a base drive unit, they may have a replacement for me sooner as a result.�
Sep 16, 2015
kenkamm No sir. This is clearly a mechanical sound. This is reinforced by the fact that Tesla sometimes refers to it as "bearing noise." It has a distinctly different sound from any of the electrical noises I've heard.�
Sep 16, 2015
Zextraterrestrial yours may be.
pretty sure the cicada (milling?) is electro-mechanical though, like a resonance that develops in the inverter.�
Sep 16, 2015
mknox I wonder if we're talking about the same thing? Since the whole drive train is always connected and spinning, why, for example, do I only get the sound when under power and not when coasting or under re-gen if it is mechanical?�
Sep 16, 2015
yobigd20 The "milling sound" is caused by a bearing that gets worn and goes bad. It does sound electrical though , like phone interference. Some describe it as cicadas. It's not a grinding sound. I don't know what "mechanical" would sound like. I'd describe the "clunk" issue more like a mechanical one.�
Sep 16, 2015
Zextraterrestrial so how is a bearing dependent 100% on Kw power draw? there are 2 types of 'milling'
I think the bearing issue is the Elon fixed w/ a shim one and the other is?? replace DU and hope it doesn't happen again too soon�
Sep 16, 2015
kenkamm Simple. A worn bearing develops slop. A sloppy bearing causes a variance between two gears, for instance. The distance between those two gears must be tightly controlled to remain quiet. The sloppy bearing allows the clearance between the gears to move away from optimum, and a noise results.�
Sep 16, 2015
mknox Yeah, but why on a drivetrain with no clutch or torque converter that is solidly connected does it only occur when under power? On smooth, flat roads, I can turn it on and off like a switch with the accelerator pedal as I coast along. I do not get it all all under any level of re-generation. Wouldn't a mechanical noise be present whenever the whole mechanism is spinning?�
Sep 16, 2015
kenkamm As an example: When motor power is applied, the sloppy bearing allows the two gears' mesh to change unfavorably. Gears tend to want to distance themselves under power. If the bearing is allowing relative movement because it's worn, the gear mesh may part slightly, only under power. Gears like these need to be very carefully aligned to wear properly and remain silent. When motor power isn't being applied, the worn bearing allows the gears to mesh back together to proper alignment, and the noise goes away.
Another example. These gears are spiral cut (like all modern transmission gears, because it's quieter.) Thrust bearings are required because the gears want to move axially under power. If it's a faulty thrust bearing, it will make noise when put under the stress of the pressure applied to it when the gears are under power from the motor.�
Sep 16, 2015
mknox Fair enough... that does make sense. At least in my case Tesla has said they will replace my DU once they have parts and can schedule me in.�
Sep 16, 2015
Cyclone My non-Performance drive unit had the "milling" sound in low-power drive or regen. It was easier to reproduce for testing in drive though since I could "hold" power in the range needed than I could hold regen in that range.�
Sep 16, 2015
kenkamm Well I'll be darned. I just got a call from the Rockville MD service center (should I mention who called me?) and they explained that they want me to be happy with my car, and have scheduled me for a DU replacement at 9 AM on October 9th.
I have to say, the Rockville guys have always taken care of me in the end. A couple of times it has taken a little bit of negotiation, but now that they have agreed to replace my DU I can say that they have addressed every concern I have had to date.
Feeling much better now about my car and Tesla.�
Sep 16, 2015
yobigd20 in the 3 or 4 DUs now that i've had that had the milling noise, one of which was EXTREMELY excessive, the milling noise NEVER occurred during regen. it was only when power was > 0kW�
Sep 16, 2015
KidDoc Here is a recording of my DU noise I recorded with windows down in a parking garage so you can really hear it fairly well. I just got a new DU last week and it works great.
Tesla Model S new noise - YouTube�
Sep 16, 2015
Gizmotoy Tesla seems either unusually proactive about this issue or worried about the public perception of it. If you post about a DU problem here, you pretty much always get a call from your SC (presuming they can link your username to real name). A week or so ago I mentioned that my clunking noise had started to return after being replaced and got a call... which reminds me, I still have to return their call. Whatever the reason, it's nice that they seem to care our issues are being resolved.�
Sep 16, 2015
Cyclone It wouldn't be the first time I've been wrong and likely not the last, so I am open to the idea that I am remembering incorrectly. The repair order shows I got the car back from milling sound review on June 2nd. In August the drive unit was replaced for the clunking sound and that most definitely occurred in drive and regen (it was the transition between the two). Given the more recent issue, perhaps I'm remembering wrong.�
Sep 16, 2015
AmpedRealtor I'm glad you were taken care of, but it shouldn't have required you posting your dissatisfaction to the forum just to have one of Tesla's forum stalkers escalate the issue. If Tesla really wants owners to be happy, they shouldn't give them the runaround in the first place!�
Sep 16, 2015
Max* It's much cheaper to only deal with the loud complainers�
Sep 16, 2015
apacheguy If you're right then that might explain why they've been slow to address the root cause. Replacing a bearing is a small cost to them so they likely placed low priority on the permanent fix.�
Sep 16, 2015
Cyclone Perhaps, but if they have to send the drive units to Freemont for remanufacturing (to replace the bearing), that shipping can't be cheap. Or maybe they can replace the bearing at the SvC, but then why aren't they replacing the bearing and giving people back their own packs rather than replacing them? Maybe the labor cost is too high per repair and they wait till they have a stack of them to fix and one day a tech does nothing but replace bearings?
Any way you cut it, it would be much cheaper for Tesla to find a permanent fix.�
Sep 16, 2015
taurusking @kenkamm :::: Glad they took care of you.
Is this why they have the $200 deductible for ESA in the first place...Probably they want to hear only loud complainers???
I had my DU replaced once in March of this year and my second one has already started making noise at low speeds...
I am thinking I will drive little longer ..�
Sep 16, 2015
dsm363 My P85 has developed the milling noise and Tesla won't fix it.
There are legitimate issues but you seem to pop up on every thread dealing with a negative aspect of the car, ownership..etc. The car is far from perfect (nothing is) and there are legitimate gripes with Tesla but you seem to focus on everything negative.�
Sep 16, 2015
kennybobby Excellent description. There is no thrust bearing--they use deep-groove radial ball bearings, hence the worn bearings and noise. The thrust load changes directions axially on the gear shafts when going from accel to regen and vice versa, so the bearings on either end of the shaft see this load reversal, but one end is carrying most of the load under acceleration and likely gets worn first. If the wear gets great enough then the shaft can slide such that the gear makes contact with the inside of the gearbox housing--that makes a milling sound and leaves aluminum flakes in your gear oil.�
Sep 16, 2015
qwk The first video posted is not the milling noise, it's the "drone". The second video is the milling noise.�
Sep 16, 2015
sorka I just hope Tesla fixes this issue before the first units hit 8 years. It's nice that they're replacing DUs to keep customers happy but I'd be happier if they never had to be replaced in the first place.�
Sep 16, 2015
AnOutsider :smile:�
Sep 16, 2015
AZbba Oh I'm sure they will fix it. With all the new cares with 2 du's this is going to be affecting a lot of cars.
Mine has gotten pretty loud. I took it by the SC about a month ago they confirmed it was the milling noise and ordered a replacement DU. Haven't heard anything, so I called them (took a few tries on different days to actually get them to pick up the phone) and they said it had been ordered but they can take 4-6 weeks to arrive. I explained that the sound was getting very loud and they said they would ask the parts department to expedite it.�
Sep 16, 2015
CHG-ON I wonder.
It seems to me that the Eastern US Tesla service centers have way poorer service than we have in CA. And I am not trying to smug, honestly. But when I read through all these posts, it always seems like the Eastern SC's are jerks about this stuff. Now, yes, I do live right next to Silicon Valley and I do use the Sunnyvale SC. But I have never gotten anything but the most amazing service. Also in Burlingame...both are close to HQ and the factory. They never argue with me at all, pick the car up for free and give me an equal or BETTER loaner, keep me updated at LEAST once a day and deliver on their promises. I even had a Pano roof seal issue for which they brought in a "glass specialist from the outside because we couldn't figure it out". I'm not kidding. For free. As it should be.
It really pisses me off, actually. Because it sounds like the good old dealer model all over again is happening as they get farther from the Mother Ship. Typical, I guess. My recommendation would be to call HQ in Palo Alto:
Tesla Corporate Office Headquarters HQ
Tesla Motors
3500 Deer Creek
Palo Alto, CA 94304 USA
Corporate Phone Number: 1-650-681-5000
Fax Number: 1-650-681-5101
Customer Service Number: 1-877-798-3752
and raise hell. We ALL deserve the best service, no matter where we are. If there are SC's out there that suck. They need to know. And you deserve to have your needs met.
Period.�
Sep 16, 2015
SeminoleFSU that's where I was... milling/buzzing noise along with the heavy groan/droning above 70MPH for quite a while, then when the clunk developed they swapped out my DU with a refurb and replaced the motor mount. It has made a huge difference, and I'm not looking forward to any of those noises coming back.. I love my car the way it is right now- it sounds like the new(er) loaners I get.�
Sep 16, 2015
supratachophobia Whoa, whoa, whoa.... Columbus, Ohio is top-notch and we are close to the east coast. Now, you west-coasters have Denver bringing you down. Go take care of them before you start ragging on the east coast.
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I will admit that one should not have to post on here in order to get something done. There are a lot of things going on in every service center. I don't want to make-up excuses, but I find it hard to believe they flat out refused service on a clearly bad drive-unit. And by 'bad', it could simply be out of spec, but that is still unacceptable since it didn't always do that.�
Sep 16, 2015
Cyclone Exactly my case, even the motor mount being retrofitted!�
Sep 16, 2015
Lyon My P85 has developed the milling noise and Tesla won't fix it.
Are they having issues with the Dual motor units as well?
I honestly didn't know non-performance DUs were affected, thanks for the info.�
Sep 16, 2015
apacheguy Not sure about the base dual motor config. But presumably the early PDs would be affected since they share the performance unit of the single motor Ps.�
Sep 17, 2015
Oyvind.H My s85 swapped DU at a20.000km. Milling noise started again recently at about 35.000km.
Teslas inability to fix serious problems permanently is my main concern for Teslas long term survival. I'm obviously betting they will fix it somewhere down the line as I still recomment Tesla and I`m picking up a Model X soon, but I'm not 100% confident.�
Sep 17, 2015
Dennis87 Not exactly the same, autopilot cars have another Drive Unit revision. The part number must end with -M or later. Also in the part catalog it is described as high speed (for 155mph use). Another difference is the motor mounts.
Tesla have many revisions of the drive unit so it has been improved.�
Sep 17, 2015
pgiralt Lets not generalize. The Raleigh service center has been the absolute best. With so many issues I've had with my car over two years, they have always been extremely accomodating even with the 5 DU replacements (all for either milling or loud hum issues).�
Sep 17, 2015
davidc18 Have to disagree as well. Our local SC (Dania) has been fantastic.
�
Sep 17, 2015
zax123 Tesla didn't replace mine until the car stopped moving in the middle of the road... Even though I told them about and they had heard the milling noise.�
Sep 17, 2015
yobigd20 just listened to it myself. agreed the video posted above, the toyota rav4 ev noise is the drone noise, not the milling noise.�
Sep 17, 2015
hpham007 So by not replacing your DU, they turned an annoying issue into a dangerous one. Nice.... If it's any consolation, Consumer Reports says the issue is DU insignificant so that should make a lot of S owners feel better.�
Sep 17, 2015
dsm363 Does your Model S have this issue?�
Sep 17, 2015
zax123 I agree that it was kind of strange on their part. Kind of a funny story... The milling noise was getting worse and worse. And that morning, my girlfriend drove me to the airport. I told her on the way that if the car dies, here's the number to call, etc... cuz I suspected that it was almost done.
While I was boarding the plane, I got a call from my girlfriend: "The car died in the middle of the street."
She called Tesla and the service center picked up and it was ready with a new DU that afternoon.
But still, they could have changed it once they'd heard the sound, and avoided the whole ordeal. In the end, it cost them more what with the tow/loaner/etc.�
Sep 17, 2015
LucM I just got my car back from its annual service visit (1st visit, a tad over 20k miles). A couple weeks ago I started hearing the drone noise, it would occur at low speeds and only when power was applied. It would go away after 35 mph (or at least I wouldn't hear it above that speed). The service advisor said they heard it, but it wasn't the "bad" sound and I should be okay. I wasn't thrilled with the answer and I will be bringing it back to them if the sound gets worse. I've made alot of long trips in this car and now a worry is kind of hanging over my head. I've also managed to convince two people to buy the car after short test drives but I can't see giving anyone a test drive while the car is making this noise.�
Sep 17, 2015
Bobbyducati Ive noticed this too, living in the same area as OP, ive talked to the people at the SC, one thing i noticed when asking about the loaner if i needed the car fixed/serviced, and they told me they never had MS loaners. I thought this was odd since thats all i hear about on here is getting really nice loaner cars, usually better than the owners actual car. Small gripe i guess, but there does seem to be a difference in service levels.�
Sep 17, 2015
kenkamm Is there a way to edit my thread title? I would like to indicate that the issue has been resolved.�
Sep 17, 2015
MrClown The west coast considers Denver to be "east coast" and the east coast calls it "west coast." I would prefer not to be associated with a coast myself. :smile: Regardless, I've found Denver service to be good on multiple occasions, even before ownership.�
Sep 17, 2015
efusco Glad to hear this! Title updated.�
Sep 17, 2015
apacheguy @ken - Once you have your new DU in place and service invoice in possession would you mind posting the HW rev of the new unit? Should be listed on the paperwork.�
Sep 17, 2015
supratachophobia My guess on this is because on the dual motor setup, the rear unit is not operating at the same high level the single motor cars need to. This either stretches out or eliminates the stresses that cause the problems.�
Sep 17, 2015
kenkamm I'd be happy to.�
Sep 17, 2015
CHG-ON Whoa, whoa, whoa.... Columbus, Ohio is top-notch and we are close to the east coast. Now, you west-coasters have Denver bringing you down. Go take care of them before you start ragging on the east coast. :smile:
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Originally Posted by AnOutsider
:smile:
I will admit that one should not have to post on here in order to get something done. There are a lot of things going on in every service center. I don't want to make-up excuses, but I find it hard to believe they flat out refused service on a clearly bad drive-unit. And by 'bad', it could simply be out of spec, but that is still unacceptable since it didn't always do that.
1: Perhaps it is just some SCs that are not up to snuf. As a heavy investor (for me), I am happy to hear this.
2: I actually posted a question about my aforementioned Pano problem and Tesla looked up my VIN from my signature, found me and emailed me about bringing the car in for service. I had not called them yet. Now, THAT is service. I was stunned.�
Sep 17, 2015
Sparky Still love this car after 30mos but, my milling noise seems worse than the video. At slow speeds, it's almost a power-steering screech and a bad advertisement for the quiet power of an EV.
Also have a tolerable "drone" but recently developed a slight clunking. During my last annual service, the Van Nuys SC explained the noise was "within tolerance".
Perhaps there's no geographical correlation with service attentiveness.
I recently completed a 700 mi trip and now the milling is noticeably worse. Two emails so far to Van Nuys SC asking them to schedule another visit to look at this again.
Crickets.
I have a cross country trip coming up in Nov and each day am a little more concerned about the car dying somewhere on the way.
I guess I'll try getting someone on the phone next.�
Sep 18, 2015
kort677 FWIW: it took a lot of effort for me to get the drive unit replaced, only after moving up the chain of command at Tesla did the service center begin to make the proper moves in order for them to get the problem attended to. It is a shame that sometimes you need to become that "squeaky wheel" in order to make people do their job properly but if that is what it takes that is what has to be done. Congrats to the OP and hopefully the mother ship will get ALL the satellites into proper orbit so people don't need to go through an ordeal to have a very common and well known issue resolved.�
Sep 18, 2015
GSP This theory of failure suggests the bearings were undersized for the thrust loads, or perhaps a bearing manufacturing quality problem.
It also suggests that owners can prolong life by accelerating gently, with perhaps occasional hard acceleration events. Reality can often be more complicated, but this theory sounds likely, to me at least.
GSP
PS. It also suggests that Yobigd20, with about 4-5 drive units replaced so far, is a hard driver. Who would have guessed? LOL. Nothing wrong with that, of course. :smile:�
Sep 18, 2015
hpham007 Maybe if we keep bumping this thread up, you'll get a phone call from a SC like the op did.
:smile:�
Sep 18, 2015
Cyclone Or is a high mileage driver!�
Sep 18, 2015
JakeP My 2012 non-performance 85 just started the milling noise at 42,600 miles, at very low speeds. I thought I was imagining it, until my 11-year-old daughter said "Dad, this is the same noise that the Tesla Taxi in Amsterdam made!". Called in to Cleveland Service Center, hope it can be addressed before it becomes a more significant issue...right now it is fairly quiet, and hopefully doesn't pose any sort of mechanical threat.�
Sep 18, 2015
scaesare I'm going to voice my appreciation for the way that the folks at the Rockville, MD Service Center have responded to me as well. I happen to have the electrical whine[1] surfacing on my (replacement) DU as well, and they are in the process of getting another one ordered to swap it out. Their service has always been top-notch for me.
If, as the OP said, the issue is the call being made at Tesla HQ after hearing the recordings sent to them from the service center folks, then that may be where some of the problem lies. I sincerely hope that HQ recognizes that "getting progressively noisier" should not equate to "within spec", regardless of the mechanical performance of the unit... especially when we are talking yhids happening in many cases within a few 10's of thousands of miles...
[1] I deliberately am using this term, rather than "milling", as that implies a mechanical sound to me which I feel more strongly describes the bearing noise, which I had previously. This is an electrical power-delivery noise... as can be heard on other electrical devices with windings or high-power electronics.
�
Sep 18, 2015
qwk The undersized bearing theory makes a ton of sense, but the much detuned Rav4 EV has the same problems. It's probably a bearing quality issue. Tesla started out with $ bearings which were crap, then they probably went to the next step which were $$, and so on. This is most likely another example where cheap becomes extremely expensive.�
Sep 18, 2015
mknox The fact is, I am the furthest thing from an aggressive driver. I never accelerate hard and just maintain an even flow with traffic. And mine is a non-P model. Yet I have the "milling sound" quite loudly and am waiting for my 3rd drive unit now. I'll defer to the experts here, but I still contend the sound seems "electrical" and not "mechanical" to me. I will definitely see if my Service Center can shed any light on the nature of the problem if/when they ever get me in.�
Sep 18, 2015
Cyclone I thought I read in one of the threads on the sound that someone was told the sound is essentially both. Basically, the bearing will, over time, get some slop and this in and of itself doesn't cause the noise. However, this now provides and avenue for an electric arc across the bearing and this is what is causing the sound. Overtime the electrical arc over the bearing could lead to an eventual mechanical failure of the bearing. In that thread, there was talk about how this should be a ceramic bearing to avoid the potential for the arc.
�
Sep 18, 2015
kenkamm This makes no sense to me. No drive bearing should have current running through it in any case. It's not like there are lightning bolts shooting around in there and the bearing gets in the way. The motor has windings that are completely enclosed.�
Sep 18, 2015
Cyclone Makes no sense to me as I'm not an EE. In my post I quoted one of the posts where the conversation of it took place. If I interpreted wrong in that thread, forgive me. I would love for that other conversation to be explained to me so I can understand better.�
Sep 18, 2015
kenkamm I'm not a EE either, but I am a ME. Where did this bearing electrolysis data come from? I'd like to read more about it.
I can tell you that in designing a mechanical system, I certainly wouldn't design something that relied on electrical current flowing through a bearing, or even allow that scenario to occur in a failure mode. Of course it's impossible to predict every possible failure mode, so who knows what could be going on that Tesla didn't anticipate. But I'd like to know more about this electrolysis theory, if that's what it is.�
Sep 18, 2015
hpham007 If there is a specific cause, only Tesla knows and they are not letting anyone else in on it. It could be a cheap fix or it could be catastrophic. The only thing we know that's true is that two of their prior explanations were b.s. If I remember correctly, one was that it was a loose wire that simply needed to bracketed down and the other was that it just needed a 50 cent shim. If either were true, there would be no repeat failures.
:smile:�
Sep 18, 2015
AmpedRealtor Agreed. Elon said this during an earnings call. None of my issues were related to anything being loose, and my service center even said that the droning noise is a bearing issue. This was long before the milling noise appeared. At least with all three of my DU replacements, none were for the reasons Elon mentioned in that earnings call. I, too, don't believe Elon's statements regarding this issue.�
Sep 18, 2015
Cyclone Follow the link in supratachophobia's post I quoted to that thread and see the conversation around his/her post.�
Sep 18, 2015
kenkamm Am I blind? I don't see a link. But I did find the thread with a search, and the only mention of "electrolysis" was his, and he did not give a source. Did he make it up?
Low Speed, High Pitch Whine�
Sep 18, 2015
Cyclone When there is a quote, there is a blue "double-arrow" next to the person's name. That will take you to the actual post in whatever thread it came from. That is the link I was referring to.�
Sep 18, 2015
kenkamm So yes, I am blind!�
Sep 18, 2015
JakeP FWIW, Tesla Service told me today that techs have been sent to training for how to open up a DU and fix the milling noise in the Service Center, though current practice may still be to replace with a remanufactured DU, and send the faulty/noisy unit back to be fixed, and then recycled as a reman unit. They assured me this does not pose an issue until it gets much noisier, and they are sending a Ranger out to record it the week after next (I am out of town next week).�
Sep 18, 2015
Cyclone Well, I could have been more clear on that too. I didn't notice the "Junior Member" flag on that, and I sure as heck didn't know that when I was a junior member not too long ago!�
Sep 18, 2015
qwk I think that someone once posted that the milling noise was caused by current getting in, and going through the rotor bearings, thus wearing them. This is probably where the current iteration of the story came from.�
Sep 19, 2015
mhpr262 A bearing issue? Not good ... several years ago BMW Motorcycles Division installed a batch of faulty wheel bearings in the single-side swingarm of some of their models, which caused the rear wheel to begin to wobble over time and in some cases to come loose. One or two even caught fire, due to extreme friction. BMWs, and BMW riders, are STILL mocked for that in my motorcycle forum ... :biggrin:
I hope it was not due to somebody at Tesla pinching pennies in the wrong place, and buying bearings that "still met the qualifications" from the lowest bidder ...�
Sep 19, 2015
supratachophobia Agreeing with your agreement as usual. I've heard the bearing noise is caused by un-anticipated electrolysis inside the motor that eats away the bearings over time.
- - - Updated - - -
That effect is called electrolysis.�
Sep 20, 2015
kennybobby from Amped Realtor:
"Four distinct problems in the drive units that keeps recurring even with remanufactured units - drone above 65 MPH, clunking noise, milling noise, and high-pitched electrical buzz under 25 MPH."�
Sep 20, 2015
Soolim In an industrial environment where large induction motors are control by VFD, the high frequency generated by the VFD (harmonic distortion) induce a high voltage over the bearing and cause the bearing pitting and ultimately to fail. The known solutions to such problem are:
1. use motor with a ceramic ball bearing.
2. Grounding brushing on the motor bearing body to shunt the induced voltage to shaft.
Background information if bearing noise is to be blamed.
For typical industrial motor (for north america), the fundamental frequency is 60Hz. The motor speed is a function of the frequency applied, varying the fundamental frequency from 0 to 60Hz changes the motor speed. In generating the varying frequency by VFD, AC is first converted to DC by converter, and then the DC bus voltage is pulse width modulated to produce the varying frequency by an inverter. The inverter chops the DC voltage to produce the fundamental frequency but also generates harmonic frequency of several orders, 3rd to 50th. The harmonic frequency is the culprit in this induced voltage across the bearing if not properly grounded.
Tesla VFD DC bus voltage is supplied by the car battery, therefore no need for the AC-DC converter, but the DC-AC inverter is required. Tesla drive motor runs at tens of thousand RPM, much higher than the typical 1800RPM of industrial motors, therefore the fundamental frequency of the VFD is already much higher than 60Hz. I don't have the exact number, but the theory is valid. This higher frequency VFD also generates higher harmonics, aggravating the bearing arcing problem.
Others claim that the whinning noise is from the gears, please refer to their post for further insight. The exact cause of the noise is yet to be determined.�
Sep 20, 2015
kenkamm Fascinating stuff!�
Sep 21, 2015
mknox I was told I would have to wait until they got a replacement DU in, and that it wasn't a really high priority. That was some time ago, so maybe the delay I'm seeing has to do with this on-site fix and getting the necessary parts/training. They said it was only "cosmetic" hence the lower priority, and I am okay with that as long as it's true and I'm not a DU failure waiting to happen.�
Sep 21, 2015
apacheguy Wasn't there something about a "new and better fix" (along with the embargo) on the way a month or so ago? Sounds like a reengineered component that will likely require a new DU install. But who knows maybe they can retrofit.�
Sep 21, 2015
yobigd20 in my opinion, Elon's answers were total BS to quell the media. I bet it's more like "several cars" needed a bracket and a shim while 99% of the other cars exhibiting this issue are the bearing problem that Elon conveniently left out of describing to the media. It seems to me to be more of a fleetwide design defect, which is pretty catastrophic if the media gets wind that the situation had not been improved and if anything it's is getting worse and much more widespread as the community starts racking up the mileage and the bearings start to get more worn.�
Sep 21, 2015
AmpedRealtor Totally agree. I was trying to be diplomatic earlier, but you nailed it.�
Sep 21, 2015
hpham007 This is no way scientific but it seems like the majority of the owners are seeing DU replacements at the 2 year mark. While I'm not sure if its a fleet wide issue, if 2014 models start showings signs of DU failures next year, then that would be more evidence supporting your view. A bigger question is if this issue has been resolved for the Model X and are we confident that DU failures will not occur in the SUV?�
Sep 21, 2015
mknox Annual for me, but I do drive about twice the "average" (24,000 miles a year). Hence my guess is that it's mileage-based.�
Sep 21, 2015
Vitold Interesting read. From what I find this is not a new phenomenon and there are ways to mitigate it. Specs of VFD motors I could find on line list bearing life (L10) of 20000 hours. 20k hours is 700k miles at average speed of 35mph.
Considering that VFD motors can be maintenance free for a long time it's possible that certain revisions (models?) of Tesla's motors may have issues with shaft grounding which is why some cars had noise fixed - by replacing worn-out parts - only to reappear since cause of the issue (bad shaft grounding) has not been addressed.�
Sep 21, 2015
kort677 agreed, there has been a very high rate of failures, if I recall even one of the auto mags had it happen to them of their long term test "ride".�
Sep 21, 2015
hpham007 I just found this interesting video. It shows that Tesla do use ceramic bearings. Would that eliminate the electrolysis theory? Or are the bearing races still metal and experiencing electrolysis which would wear away the ceramic balls?�
Sep 21, 2015
kennybobby Great find on the SKF video and the ceramic bearings, thanks for sharing.�
Sep 21, 2015
Soolim Yes, I pointed out in my post that ceramic ball bearing is one solution to mitigate VFD harmonic current induced arc pitting (also called electrolytic corrosion), and confirmed by the SKF video. Bearing race electrolytic corrosion is unlikely due to the gap created by the ceramic balls.
Strangely, starting at around 5:00 of the video I could hear some whinning:frown: Not sure where the video recording mic is picking that sound.�
Sep 22, 2015
Vitold We are back to square one. Since electrolytic corrosion is not affecting bearings or races something else is causing the noise.
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70D uses Tesla's newest motors and it would be interesting to know if 'milling noise' is affecting 70D owners as well.�
Sep 22, 2015
cab For those of us considering pre-owned Teslas this is all doubling concerning and that concern is further driven by the lack of any third party repair shops, parts availability, shop manuals, general "repair cost" info, etc. For me when considering these kinds of cars used (as when I bought a pre-owned M5 w/o a warranty) it all comes down to assessing my exposure/risk. The Model S is a black hole in this regard right now.
1. Can the drive unit be repaired vs. replaced? Don't know, but presumably based on what we have all read.
2. How long does repair/replacement take in labor hours? Don't know.
3. What does the repair consist of? Don't know.
4. What parts are needed and what do they cost? Is there a core charge? Don't know.
5. How likely is it that this repair will be needed during my ownership? Don't know, but it sure seems like an awful lot of folks are encountering it.
6. Are special tools required to perform the repair or is there any kind of special procedure needed afterward to calibrate or set up something?
My M5 was a repair magnet, but there was only ONE item that was generally a pain if if it broke - the transmission - as there were no repair parts available (i.e. meaning you had to replace the entire thing). Fortunately, the incidence of complete transmission failure was very low so that risk was minimal. Everything else (and there was a lot of it), I was able to address myself.
While a pre-owned car might still have this under warranty for the next few years, it will, minimally, become an issue for resale if these questions aren't answered...�
Sep 22, 2015
davidc18 I'm not sure how to categorize the noise, but our 70D has been into the service center twice for noise from the front engine. The first time after the test ride they said the noise was not normal and would order a replacement, which they planned on doing during the 5000 mile tire rotation. At just over 5000 miles, with the noise much louder, they decided it was now normal. Close to 7000 miles and the noise is now audible at all speeds and is loud enough to be heard at 75+ mph. I'm now waiting to see just how long I can stand the noise before trying with the SC again. Perhaps the unit will just fail and remove any doubts.
�
Sep 22, 2015
AmpedRealtor So it would appear that an entirely new motor design is also exhibiting noise issues. Did someone at Tesla order their engineering degree from Fiji or something?�
Sep 22, 2015
Tupelo My '14 S85 with 18,500 miles has developed the noise. It sounds like an electrical "buzzing" noise when power is applied during acceleration, and rises as the speed increases. It's getting louder and is occurring now over a longer power/speed band. It goes silent when I ease up on the accelerator (0 kw applied) or regen engages. I'll take it to my SC and see what they advise. Sadly, I feel like I drive around now in a broken car and it really diminishes the enjoyment I've experienced being a Model S owner.�
Sep 22, 2015
Vitold This could mean that it's not a motor but gearbox that is making the noise.�
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