Weird rain damage

[cdhowe]

Hi all,

I took delivery of an arrest-me red AWD Model 3 for my wife on September 7 (I already have a model S). She was skeptical at first that she'd be able to figure out how to operate the car, but now loves, loves, loves her model 3.

However, we did have some serious downpours yesterday here in New England. She drove through a lot of water on the road to pick me up at the train. When we left the train station, I said, "I think I hear something dragging". We pulled over, and sure enough, I can see something hanging down from the rear motor and scraping along the ground. We drive slowly home and I crawl under the car to get a better look. The attached photo shows what I saw.

Now to be fair, this looks worse than it really is. What's hanging down there is a piece of material I can't identify that seems like it was originally covering the rear motor. My theory is that it wasn't attached properly at the factory and as it got waterlogged with water from the flooding around town, and it just fell farther and farther down until it contacted the road. After that, it bounced up and down, which caused it to tear.

My wife assures me she never contacted any sticks, rocks, or pavement in the water she went through, so I don't think this is the result of her hitting anything.

Service center is ordering the part and will replace it when the part comes in. I'm letting the strangely absorbent material dry out and will duct tape it up for the drive to the service center so it won't contact the road any more (nice thing about electric cars: things underneath the car don't get hot like with exhaust pipes).

I'm mainly curious at what this part actually is and whether anyone else had run into this cover coming undone or detaching in heavy rain. If you have a model 3 and get a chance, I'd love to see what that cover looks like properly attached; I never took a close look at what the rear motor undercarriage looked like before this. I'd be interested in any insights you'd care to share.

All I can say is that at least we didn't have a waterlogged bumper fall off....

-C

 

[JasJ]

It could have been worse....

https://jalopnik.com/bumper-falls-off-brand-new-tesla-model-3-after-30-minut-1828306917

 

[TeeEmCee]

Had something similar happen to me years ago in a Volvo. That underbody shield must have been fastened improperly and she must have driven through a deep puddle. If water hits under that shield, it can exert a lot of pressure, even at moderate speeds, and it ca rip the fasteners or the shield itself.

Judging from the shape of the tear, the shield material also doesn't look all that strong, probably the usual cheap Tesla stuff. In my case, that one time, I managed to tear off a solid plastic shield, despite the low speed. The pressure exerted when water gets to push from under the shield is indeed significant.

No more driving through puddles at anything but very slow pace!

 

[nullgel]

The same thing happened to me tonight. Any updates in the month since you first posted?

 

[SMAlset]

Don't think it's anything the wife did driving. And glad to hear she loves her car! Me too and I wasn't sure since I'm a Model S fan.

There is at least one if not 2 threads already on this issue somewhere in the Model 3 area (complete with photos). You are not the only one experiencing this, and I suspect with rainy or wet, snowy season ahead now, we'll see more. From what I remember reading, the thought was the water splashed up, got soaked into the covering and it became heavy and the rainsoaked material then pulled down through the fastners and leaving the material dragging. I asked a Mobile tech about this after reading about it on TMC and he had not heard of it yet, but then we haven't have rain yet here in the SF bay area.

 

[AlanSubie4Life]

Are all the attachment bolts present? There should be 4 in the front and 2 in the rear. For the rear cover...

If any are missing, the most likely thing is that the attachment bolts were not tightened at the factory and the whole thing started flapping in the breeze and finally broke. If they are all still there then maybe some debris damaged it.

My car was missing a bolt at delivery. And the rest seemed a bit loose.

P3D+ Issue: Front Undercarriage cover came loose (while driving)

 

[N54TT]

I’ve seen a couple posts about this. I know the OP said nothing was hit. But one of the other posters that had this happen speculated that the front edge of the felt material was hanging a bit lower and that’s what’s caused it to catch something. The thought of putting a strip of duct tape along that front edge to reinforce it...on a car I paid $74k is kinda crazy. I’ve checked mine and it doesn’t hang any lower. But seeing more posts about this happening.....I think I might rather do that anyway, and forget about it, than deal with this potential issue.

 

[cdhowe]

I'm the original poster. I'm at the Watertown Tesla Service Center today, and they are replacing the shield. Ironically, I had to drive through the Nor'easter slush to get here including several deep puddles, but the Gorilla tape I used to tape it up seems to have worked like a champ to get here.

I concur with the suspicion that the bolts weren't all fastened correctly or one or two were missing after final assembly. We had a couple manufacturing defects we've had to have corrected (including the wheels being pretty far out of alignment), so I think we just had a bad day on the assembly line when they built this car. That said, Tesla has been working very hard to make it all right and to ensure we're happy, so I'm not feeling bad about the experience at all -- I just view it as part of the early adopter experience. And the car itself is so amazing to experience that we haven't minded the teething.

I'll update if the repair expert tells me anything about the part once it's been replaced.

 

[wbhokie]

So you have rain damage and took it to Watertown? Coincidence?

 

[plasmo]

Hi all,

I took delivery of an arrest-me red AWD Model 3 for my wife on September 7 (I already have a model S). She was skeptical at first that she'd be able to figure out how to operate the car, but now loves, loves, loves her model 3.

However, we did have some serious downpours yesterday here in New England. She drove through a lot of water on the road to pick me up at the train. When we left the train station, I said, "I think I hear something dragging". We pulled over, and sure enough, I can see something hanging down from the rear motor and scraping along the ground. We drive slowly home and I crawl under the car to get a better look. The attached photo shows what I saw.

Now to be fair, this looks worse than it really is. What's hanging down there is a piece of material I can't identify that seems like it was originally covering the rear motor. My theory is that it wasn't attached properly at the factory and as it got waterlogged with water from the flooding around town, and it just fell farther and farther down until it contacted the road. After that, it bounced up and down, which caused it to tear.

My wife assures me she never contacted any sticks, rocks, or pavement in the water she went through, so I don't think this is the result of her hitting anything.

Service center is ordering the part and will replace it when the part comes in. I'm letting the strangely absorbent material dry out and will duct tape it up for the drive to the service center so it won't contact the road any more (nice thing about electric cars: things underneath the car don't get hot like with exhaust pipes).

I'm mainly curious at what this part actually is and whether anyone else had run into this cover coming undone or detaching in heavy rain. If you have a model 3 and get a chance, I'd love to see what that cover looks like properly attached; I never took a close look at what the rear motor undercarriage looked like before this. I'd be interested in any insights you'd care to share.

All I can say is that at least we didn't have a waterlogged bumper fall off....

-C

This was also posted on twitter regarding snow damage... is this the same thing?

 

[AlanSubie4Life]

It would have been helpful to know if the bolts were still there, in the snow damage video. I do wonder whether there is enough room even for a well attached sheet to allow enough snow in (particularly from the wheels dumping snow onto the top of the cover?) to weigh down the sheet and rip it off. If so, people are going to need to look at replacing these covers with thin aluminum or making the attachment points very robust. Or the design will need to be modified to prevent the snow intrusion. I’d have to look at the design to see whether it’s possible for large accumulation to occur.

So to me this looks like it was a loose cover which allowed snow to get shoved in in huge quantities, or it is a design issue which inherently allows snow in.

I guess we’ll find out, since now a lot of places are getting significant snow.

It seems like an easy enough thing to fix, and presumably Tesla will revise the design if needed.

 

[AlanSubie4Life]

Since there haven’t been additional reports I have seen for this issue, even with the recent snows in the eastern US, I suspect this problem is missing (or loose, which then fall out) bolts, which cause this damage to occur (via water or snow or wind intrusion) rather than an inherent design flaw.

 

[SMAlset]

Does this sound like a reasonable theory? Found out what’s causing undercarriage composite to break apart

 

[AlanSubie4Life]

Does this sound like a reasonable theory? Found out what’s causing undercarriage composite to break apart

That doesn’t seem like a good design, and the possibility of accumulating ice in the bumper cover in winter seems bad, but I don’t see how this would cause the composite sheet (not the bumper cover) to rip free unless there is a way for water to pool on it as well (seems that the bumper cover has this issue but composite shield seems pretty flat). I am also not sure how absorbent it really is.

The rear drive unit/suspension cover is attached with at least 6 bolts with fairly large washers, 4 in front and 2 in the rear. It looks pretty secure, as long as those bolts and washers are all present.

 

[R1Fast]

Does this sound like a reasonable theory? Found out what’s causing undercarriage composite to break apart

That's my bet too - I was just reading that thread and was going to link here. Water accumulates by leaking in thru the bumper area, then sloshes around and potentially freezes and in either case that cheap composite crap underneath can't bear the weight.

Haven't noticed this yet and I live in Seattle, but it's been pretty dry here for November. Will report back if I notice any damage in this area.

 

[Jaywlker]

That's my bet too - I was just reading that thread and was going to link here. Water accumulates by leaking in thru the bumper area, then sloshes around and potentially freezes and in either case that cheap composite crap underneath can't bear the weight.

Haven't noticed this yet and I live in Seattle, but it's been pretty dry here for November. Will report back if I notice any damage in this area.

Please do report back. I think your analysis is spot on.

 

[AlanSubie4Life]

I washed my car for the first time this evening, and my driveway happens to be sloped. Almost all the water coming off the top of the car ended up being stored in the cover.

It all seemed to drain out (with exception of maybe a few cups?) when the car was pulled into the level garage...which isn’t great as then I have a big pool in the garage.

However, I could see this being kind of a big problem for people who park outside with the car facing upslope...then it rains...followed by a freeze...seems like you might end up with a very large ice cube inside that bumper cover. Fortunately not something I have to worry about.

I actually think the drain holes would be better served somewhere closer to the back of the car to avoid this problem. But I wouldn’t drill, personally. Just always park your car downslope in wet weather I suppose.

I wonder how other cars deal with this? I guess the cover does not typically extend as far under the car, so there is no place for pollliand maybe the drainage channels are managed differently.

 

[seancarmen]

Our bumper and whole under carriage fell off in the rain!

 

[TeeEmCee]

Our bumper and whole under carriage fell off in the rain!

It would seem a proper recall would be in order.

 

[AlanSubie4Life]

Our bumper and whole under carriage fell off in the rain!

Yeah that can happen, if they don't bolt it on correctly (or at least that is our assumption). The specific items you are missing here are the rear bumper cover, and the rear diffuser assembly. These parts are attached together (though they can be separated.) Any word on the exact conditions for this failure...rain, but how much, did you drive through a lake, etc.?

I have annotated your picture. There are a total of 8 bolt/washers underneath (and there are two torx and a variety of clips in the wheel wells), it appears the attachment points for the bolt brackets have ripped off.

I'm doing this from memory so it's possible it's not correct. I do know there are 7 or 8 holes for the bolts underneath though, and I'm having a hard time finding them all in your picture, so it looks to me like some are gone. And I have no idea what happened to the image quality in the upload. It's all compressed poorly.

To me it looks like you still have at least 2 of the three bolts for the Mid Aero Cover (the thing that covers the motor), and those are shared with the rear diffuser & bumper cover assembly, so I don't really understand how this happened. It's possible that you lost enough bolts to allow a large puddle to rip your bumper off, but hard to understand exactly.



I would recommend taking lots of detailed pictures of the underside to ascertain how many bolts you actually had remaining.

It's possible the weld points at the back failed (kind of what it looks like?) and that caused the bumper to drop off and drag and that would just rip it off eventually.

EDIT: looking at one of the other pictures you can clearly see you still have the middle bolt which recent builds do not have. So you have an early build, I can tell from this picture. And the side brackets are torn out, and the back brackets are just gone.

All of this should have taken a lot of force, I think. But those bracket points at the back look suspiciously poorly spot welded. That may have been the start of a cascade of failures, because if those go there would be a lot of leverage on the remaining attachment points.

It's possible they removed a few too many welds from the production process or they were having a hard time getting them to be good quality. Or, if you drive through a pond of water, this would be the expected result even for a vehicle with good welds. (Though I would suggest that the bolt holes should have ripped out rather than the welds fail.)

Do let us know if this is covered under warranty (to me it looks like it probably should be).