Thunk while supercharging

[flyingpenguins]

I’ve searched this forum as well as M3OC and reddit without success.

My model 3 makes a periodic clunking or thunking noise when supercharging, around every 3 minutes or so. If I’m sitting in the driver’s seat, it feels like it’s coming from the right rear or the rear center. I can hear it and it actually vibrates the car enough that I can feel it.

It’s definitely NOT the same sound as the two-click high voltage connectors clicking on when I first unlock the car—it’s a single clunk and it’s a lower pitch. It’s happened with pretty much every SOC.

Any ideas as to what it might be? Is it normal?

Thanks!

 

[scottm]

Somebody locked in your trunk?

 

[Jedi2155]

It sounds like the battery contactor is going on and off. I'd call Tesla service to make sure nothing is going wrong.

 

[xpitxbullx]

Probably your battery coolant system keeping your battery temp down. It heats up after you drive it and it heats up some more when you supercharge it.

That’s just a guess.

 

[Bighorn]

Took my first road trip and noted the same metallic clunk when we supercharged. Definitely not something that happens on the Model S. Not sure whether it's normal or what it is. Car drove over 3000 miles uneventfully.

 

[Xenoilphobe]

Trunk Monkey is restless.

 

[SJC3]

Everything I’ve read indicates the contactors.first time I heard it was when I was sitting in the car waiting for a friend, I thought something like a walnut fell and hit the car.

 

[Bighorn]

It’s a remote sounding sound I’ve only heard from within the car, so far. I thought it might be the supercharger the first time I heard it, then I actually considered someone throwing things and hitting a nearby metal object [it was late at night at a rural WY supercharger] It sounds like a rap on a metal door or a closed metal container affected by an altitude change.

I’m not sure why the contactors would randomly be engaged. I noticed it more in cool environments than hot. I thought about a metal part flexing as the battery warmed.

 

[apacheguy]

The contactors must be closed while supercharging. If the contactors cycled while supercharging then you would immediately notice the amps drop to 0 and an alert would appear.

 

[scottm]

The contactors must be closed while supercharging. If the contactors cycled while supercharging then you would immediately notice the amps drop to 0 and an alert would appear.

..plus, if the contactors opened while supercharging, it might very well be the last time those contactors open. They're not rated to be opening and closing suddenly while full power is flowing. (I think they're rated for 1 cycle under full power conditions, and many thousand cycles when unpowered. So they'll act like a circuit breaker once only - the arcing will melt them). If your supercharging kW rate drops to zero immediately after a clunk... talk about getting new contactors put in.

 

[flyingpenguins]

yeah, i agree, it seems like it'd be pretty unlikely that it's the contactors going on and off while supercharging--the supercharging rate/wattage doesn't change when the thunk happens.

I thought about a metal part flexing as the battery warmed.

I was thinking the same thing too @Bighorn ...

 

[Tianshi]

I have the same experience with my model 3. I have had only 3 short supercharging sessions and each and every one has such clunking noise. Trying to contact Tesla about it.

 

[Bighorn]

I’m over 4000 miles into my current trip, sleeping in the car, and it seems there are typically 3-4 bangs in diminishing intensity. Makes falling asleep a challenge Can’t say for sure whether it happens every time, though I think not or it’s not as intense.

 

[wdolson]

It's probably the coolant pumps turning on. When you supercharge, the batteries get hot after a few minutes and the battery cooling system has to kick on to keep them from overheating. At least on the S, the fans roar after about 10 minutes of supercharging too as the car tries to suck in as much air as it can through the radiators.

In any case I've always heard clunking sounds when supercharging my S.

 

[Garlan Garner]

I’ve searched this forum as well as M3OC and reddit without success.

My model 3 makes a periodic clunking or thunking noise when supercharging, around every 3 minutes or so. If I’m sitting in the driver’s seat, it feels like it’s coming from the right rear or the rear center. I can hear it and it actually vibrates the car enough that I can feel it.

It’s definitely NOT the same sound as the two-click high voltage connectors clicking on when I first unlock the car—it’s a single clunk and it’s a lower pitch. It’s happened with pretty much every SOC.

Any ideas as to what it might be? Is it normal?

Thanks!

Take it to your service center.

 

[Garlan Garner]

I have the same experience with my model 3. I have had only 3 short supercharging sessions and each and every one has such clunking noise. Trying to contact Tesla about it.

You are trying to contact Tesla? unuccessfully?

You live in Fremont.

 

[Bighorn]

It's probably the coolant pumps turning on. When you supercharge, the batteries get hot after a few minutes and the battery cooling system has to kick on to keep them from overheating. At least on the S, the fans roar after about 10 minutes of supercharging too as the car tries to suck in as much air as it can through the radiators.

In any case I've always heard clunking sounds when supercharging my S.

I’ve got nearly 150k miles of road tripping in a Model S under my belt—sounds nothing like that or a pump coming on.

 

[Garlan Garner]

I’ve got nearly 150k miles of road tripping in a Model S under my belt—sounds nothing like that or a pump coming on.

The model 3 and Model S are totally different.

 

[Bighorn]

So I’ve charged a few times today. First time was after driving east in heat along I-10 in Louisiana. There was a medium followed by a mild clunk a few minutes into the charge. Seemed to be coming from the frunk area. The subsequent supercharges caused no clunks. It seemed like a pump may have come on soon after the first clunk.

I need to remember to get out and observe a first charge one of these days. Hard when you’re driving around the clock to have a first charge

 

[wdolson]

I had a scraping noise from the radiator baffles on my S. I recorded it on my phone and sent it to the SC. They figured out what it was from the sound. The baffle blades had some plastic flash on them that were scraping. They ordered new blades.

Probably making a recording will help. It could be the Model 3 has some kind of large relay in there that clunks from time to time?