clunking noise while super charging

clunking noise while super charging

Had our model 3 5 weeks. When supercharging every few minutes there is a short clunking noise, similar to steping on a metal can. It appears to be comming from the back half of the car.
We also have had a Model S 3 years and never heard this sound with it. Any ideas on what this may be .

Bighorn | October 21, 2018

I've queried owners a lot about this noise. It sounds to me like a metal plate undergoing thermal flexion, or somebody winging a walnut at your car:) It moves all around the bottom of the car. I've noticed it at times other than supercharging, though it's much harder to hear when driving. A very early owner was told by Tesla that it's normal but he couldn't remember the mechanism. Can happen half a dozen times, usually less loud each time, but startling if you're trying to sleep. Seems accentuated in cooler weather.

gballant4570 | October 21, 2018

May be the new load balancing system on the M3? Should come into play especially when Supercharging.

Bighorn | October 21, 2018

Doesn't sound like switches. And I'll often hear it pulling into parking lots as though the curb cut is causing flexion.

leo33 | October 21, 2018

I've heard it both while supercharging, and while driving, usually after a fairly long stint on the freeway. A couple of times it almost sounded like hitting road debris when there was very obviously none. Couple of other times it sounded like a flexing oil can. I'm very curious what this turns out to be.

mknewman | October 22, 2018

I heard the same kinds of noises during the software update. Mine did it while supercharging too.

Quinten | October 22, 2018

I had the same experience.... from what I read it is normal of some kind of relay inside? To me I was thinking maybe the brakes locking and unlocking? My does it too charging inside my grage.

freejoule | October 25, 2018

Bighorn, you described this perfectly. This describes my experience exactly.. While supercharging for 30 minutes, with air temps in the 40's, SOC 25% - 70%, mostly around 80kWh rate, I heard at least 4 walnuts hitting under the front half of the car.. every one was in a different location.. Left.. right.. middleish etc. One thing interesting in my case, there is an off camber right turn on my way home I seem to replicate the same sound..but just one knock. This case I was convinced it was metal flexing due to the weird elevation change of the turn.. but seems odd the sound is exactly the same as what I heard supercharging.

Bighorn | October 25, 2018

Exactly similar to when I've noticed it most often other than supercharging--usually pulling out of or into a parking lot while turning. Until proven otherwise, it's a metal plate. Thanks for corroborating!

Wesla207 | October 25, 2018

I'm experiencing the same thing, love the walnut analogy. Thinking about talking to my local SC about it, as today my car actually stopped charging for a moment after a clunk. It quickly flashed a message about needing to be serviced before continuing to charge as normal.

Bighorn | October 25, 2018

The very first time it happened was at night at a remote Wyoming supercharger and my thought was that some kids were throwing something at the car. Got out and looked all around. My other thought was that it was the actual supercharger acting weird. My druthers would be that Tesla describes what's going on or remedies it. I think it detracts from the overall experience. I don't yet have a sense as to how loud it is to passersby, but I expect one day to be asked, "What's wrong with your car?"

garretn | October 25, 2018

+1 on What's wrong with your car? The first time that happened to me I was sitting in the quiet car at the supercharger when I heard the loud thud like something exploded under the floor board it scared me. So much for relaxing in the piece and quiet car. :)

Thanks for the reminder I have an appointment at the service center tomorrow I will see if I can get some kind of explanation on what is going on and why it needs to happen.

Bighorn | October 25, 2018

Please report back! Seems like we should have an answer by now. Thanks

Future_owner | October 25, 2018

I have seen this answered in another thread somewhere in the forum but if memory serves it is indeed a relay that switches as each battery compartment gets charged. Definitely unnerving the first time it happens but I'd consider it 100% normal. You are sitting right on top of that battery and in my experience from dropping things on to the floorboard, the metal between you and the battery is not very soundproof so you hear everything. Since it seems like almost all of us have that same gut reaction the first time, it might behoove Tesla to include that info somewhere in the manual so that we don't all freak out. Bad roads are also A LOT more noticeable now as well and several times I've thought there was a problem with the car until I hit a different patch of road and the vibration/noise went away, I'm looking at you KY and MO!

Bighorn | October 25, 2018

There are relays/contactors that make noise. This almost certainly is not that.

Sparky | October 25, 2018

I've had similar noises while driving on a mountainous highway. It would be nice to know if it is caused by "oil canning" of the metal surfaces due to thermal flexing or pressure changes, or if it is just the sound of battery section relays.

mpratola | October 25, 2018

I had this happen to me a few days ago while charging at a destination charger (40amp, 32mi/hr). It was quite loud (as in startling/scary, similar to what @garretn said) and towards the rear, and I felt it in the floor boards (I was sitting in the passenger seat). I had only been charging 5-10mins at that point. It certainly sounded like thermal expansion to me.

For this and other reasons, I really wonder if the battery thermal management system is right on my car.

I have an August 2018 production LR RWD.

mpratola | October 25, 2018

There is also a thread over at TMC that has a video of the sound, although it sounded much louder in my case than what the video portrays (could just be the quality of the recording):

Bighorn | October 25, 2018

Thanks for the link. I added my two cents since I've been looking into this since August.

staze | October 25, 2018

Some have said contactors, coolant valves and AC pumps. Makes sense this the battery is climate controlled when charging.

walnotr | October 25, 2018

We experienced this yesterday as well. It was our third SC session of the day and the first where we sat in the car for the entire charge. I little disturbing but apparently no noticeable affect. Sure hope it’s not a precursor to a future problem as we are about 2K miles from home. I’ll be watching this thread.

Bighorn | October 25, 2018

Definitely not. It's a flexing metal plate.

garretn | October 26, 2018

@Bighorn - Tesla service center didn't know what I was talking about never had this complaint. Sounds like we need to start reprint this issue and see if they can figure out what is happening or how to insulate the noise. I wasn't going to leave the car for them to check it out.

Bighorn | October 26, 2018

That’s odd, but not the first time they’re late to know stuff.

GotLithium | October 26, 2018

This happened to me a few hours ago. 3-4 loud clunks which were more spaced as I went from SOC of 20% to 66%. After the first two then I heard a fan turning on and the sound of vents opening. Outside temperature was 52 degrees. One hour later while driving got the warning of power reduced, exit car and re-enter. Did it and got home with no other issues. IMHO this could be battery expansion with heat generated and the cooling system doing its thing. Scheduled to do latest software update tonight. Learning a new language...

mpratola | October 26, 2018

Starting to look like maybe this is tied to August builds based on what's showing up in the TMC thread. FWIW mine is an August build delivered late September.

Bighorn | October 26, 2018

July build delivered mid-August. It was confirmed to me in a January delivery as well.

Nexxus | November 14, 2018

My guess would be the sounds of the actuators/relays that start the cooling pumps, while charging, to maintain the battery temperature. The BMS of Teslas are superior to any others and kudos to the engineering team that did their homework in making it so robust that the batteries will last a lot longer than other companies' will.

Bighorn | November 14, 2018

Yeah, no. It’s flexing sheet metal. Sounds nothing like a contactor, relay, valve or any functional device.

juraj | November 18, 2018

yeah i noticed this as well after a very long road trip (400km) I stopped at a supercharger and heard very pronounced clunking sounds - it was quite cold -2 celsius. btw, i may have heard the same sounds when driving on the highway during the road trip but I assumed it was rocks hitting the bottom of the car.

Tropopause | December 30, 2018

My two-week old Model 3 MR (1,000 miles) is clunking while Supercharging.

Yesterday I Supercharged from 21%-49% after a long drive so it was the first time I tested the max Supercharging rate of the 60kWh MR battery. I was surprised, and happy, to see 118kW charge rate with tapering beginning at 35%. The clunking sound occurred every couple of minutes, with increasing intensity as the Supercharging continued. The last couple clunks were so loud and the vibration so intense, I decided to discontinue Supercharging at 49%; the charge rate was 93kW at that point.

I recorded the sound and sent to a Tesla Technician who had requested me to do so prior to bringing the car in to inspect this situation.

After reading this thread I'm not sure anything can be done but my car goes in January 11 and I'll report back here.

tony987654321 | December 30, 2018

It happened to me when supercharging and other time I lost my key card. While searching it I went back seat and kind of partially stading and same sound came. I bent down to look for key on the back seat floor and same sound came again.

Looks like base of the car is not very strong and there is some space between two metal layers. It results in metal sound when some pressure because of weight is applied.

tony987654321 | December 30, 2018

Maybe it happen while supercharging because battery cell expands at a very fast rate. If that's the reason than I am expecting my battery to go bad or catch fire before it's warranty is over so no issue.

Bighorn | December 30, 2018

So f*cking stupid some people are.

LadyGrey | January 8, 2019

Same sound, multiple times during each supercharge of our Model 3 (Jan 4 delivery), but they have all been while cold (15 - 40 deg F). I've been assuming it was flexing metal due to heat expansion. Will follow this thread.

agill | January 13, 2019

Nov 18 M3 long range dual motor. I’ve had this sound a few times during supercharging and again just this weekend during our first drive up in the mountains for ski trip. Happened a few times as we ascended and sounded as described above, like hitting a rock on the road or something like battery pack sheet metal flexing.

tbrazelton | February 9, 2019

Just took delivery of my AWD model 3 on Feb 8th. Heard the noise during my first super charge and it freaked me out. I was nervous I had been given a lemon. Sounds like this is a normal issue. Sounds like flexing metal or a relay switching in the battery pack. Would make sense as the pop is similar on my own relays around my home for my automated gecko tank.

Bighorn | February 9, 2019

Not a relay.

Red_Falcon | February 10, 2019

I just completed a 348 mi road trip - temp 28 F for the beginning of the trip. First Supercharging no noise with charging rates starting at 365 mph and SoC of 40%. Second Supercharging heard 5 or 6 clunks just like what everyone has described. They all occurred between 30 & 50% SoC when my charging rate was between 464 & 474 mph (116 kW). Once I began ramping down at 48% SoC, it stopped. The reason is exactly what Bighorn stated - thermal expansion due to rapid heating from the high charging rate. Valve, relays don't make this kind of sound, period! There shouldn't be any issues provided Tesla engineers didn't accommodate this in the design. My guess is the "clunking" noise should happen. There could be two reasons why some aren't experiencing it; 1) the joints the causing the noise are more freely able to move with respect to each other, 2) the joint simply hasn't achieved enough force due to thermal stresses to cause it to "pop" loose. I'm a bit concerned that if the joints have to build up thermal stress to cause them to "pop" loose, this over time could cause fatigue in the joint. Without any data though, this is all speculation if the "clunk" noise is an issue or not. But to repeat myself one more time - it's due to thermal expansion.

stevesy | February 17, 2019

my model 3 clunks loudly while supercharging for sure, but i was out chopping wood next to it the other day plugged in to my NEM 14-50 connector, and i swore i heard it clunk from a few feet away. then i thought, maybe folks are reporting it happening at superchargers because thats the place we're usually sitting in our car? does anyone sit in their car while it charges at home? do you get the sound then also? very curious why tesla hasn't seemed to address this yet. i took delivery in december of a long range AWD model 3.

Tropopause | February 17, 2019

I hear a similar metallic echoing sound when I lightly beat my fist against the floor of rear passenger area.

AWDTesla | February 25, 2019

I asked the Tesla ranger about this issue as it was bothering me. He said their is ports they need to access on the batteries for diagnostics and maintenance. Those ports open and close and were moved on the model 3 for easier access, making it cheaper to maintain. The clunking noise we hear is form those ports opening and closing.

LadyGrey | February 25, 2019

Our Tesla ranger acknowledged it was metal flexion, and that engineering was working on it.

Bighorn | February 25, 2019

You don’t seem to believe that your ranger was mistaken. 100%.

AWDTesla | February 25, 2019

He's probably been working on them a lot longer than you and i.

AWDTesla | February 25, 2019

and yes, it happens while I am plugged in at home. I pretty much live in my garage and hear it constantly.

stevesy | February 25, 2019

so the deal is we will never be able to sit in our charging vehicle without being terrified as we doze off every 15 minutes by the sound of an intense thud slamming the body of our car underneath us? i am starting to have serious questions about this Model 3 build. I bought a 3 because the S was so nice, but it looks like so many things in the 3 are just "yep, sorry, they had to save money so they made it suck"

AWDTesla | February 25, 2019

No offence but, you're (as I am) buying the lowest end vehicle in their line up. If you wanted S nice, you should of bought an S. I wouldn't expect M quality & performance from a BMW 328.

Bighorn | February 25, 2019

I knew about this many months before any service personnel was aware of the phenomenon. I supercharged 23k miles in the first couple months and experienced the clunk over 100 times. I know that it is not isolated to the rear of the car as it migrates around the perimeter of the top battery cover nor is it the sound of a valve or contactor. Many pages of talk regarding this on this and other websites. Tesla service has acknowledged that it's the battery cover flexing and you only hear it in cars that no longer had the insulation placed by the Flufferbot. Ask around to see how many times I've had to correct misinformation from service personnel. Dollars to donuts, the ranger doesn't drive a Model 3 nor has experienced the plate flex. It flexes with supercharging, ascent and descent pressure changes, and frame flexing. You can duplicate the sound by rapping on the rear floor.

jimglas | February 25, 2019

My X also 'clunks", due to flexing of the battery case. hard to see how this is a problem or how it makes either car "suck". Maybe you should just sell your car and buy a kia.

jimglas | February 25, 2019

My X also 'clunks", due to flexing of the battery case. hard to see how this is a problem or how it makes either car "suck". Maybe you should just sell your car and buy a kia.