Middle Rear Seat Belt Problems

[Daniel in SD]

Anyone have any thoughts on what might have gotten in there?

I am beyond perplexed. How could this substance dissolve the thread and not belt?
It appears that seatbelts are made from polyester but the thread is made from nylon so maybe there is something that attacks one but the other. Are your kids doing chemistry experiments in the backseat? Are you transporting pool chemicals?
I'm sorry for slandering the service center mechanics!

 

[ptbroderick]

As a rule, we don’t drink in the car. Even if the rule was broken and someone did spill a drink, it seems unacceptable for a drink to make the seatbelt malfunction. If that was a common occurrence, my minivan would be out of commission.

 

[Tony_YYZ]

Is it possible it’s some sort of coolant or similar substance leaking back there? The battery tent is right under the rear seats. The service tech didn’t think to maybe investigate this further?

 

[Daniel in SD]

Is it possible it’s some sort of coolant or similar substance leaking back there? The battery tent is right under the rear seats. The service tech didn’t think to maybe investigate this further?

Nylon, if that's what it is, is resistant to ethylene glycol and propylene glycol according to this table (Nylon Chemical Compatibility Chart)
OP should thoroughly clean the area, replace the damaged seat pieces (just in case they have more of this mystery chemical) and inspect regularly. Bizarre...

 

[0ptions]

Nylon, if that's what it is, is resistant to ethylene glycol and propylene glycol according to this table (Nylon Chemical Compatibility Chart)
OP should thoroughly clean the area, replace the damaged seat pieces (just in case they have more of this mystery chemical) and inspect regularly. Bizarre...

Whatever is leaking though will eventually stop leaking, because there isn't an infinite amount of this liquid in his vehicle. Hopefully it can be repeated or traced!

 

[ptbroderick]

I’m scheduled to go to Jacksonville in a few weeks and will make sure we figure out what this is. I’ll report back.

 

[Krazaak]

Nothing anybody is drinking is dissolving the nylon thread. Maybe an acetone, vinegar or other acidic spill, maybe some contaminant that had saturated the seat cushion during manufacture? Or xenomorphs... any funny looking eggs around?

 

[Daniel in SD]

Nothing anybody is drinking is dissolving the nylon thread. Maybe an acetone, vinegar or other acidic spill, maybe some contaminant that had saturated the seat cushion during manufacture? Or xenomorphs... any funny looking eggs around?

I'm going with muriatic acid (aka hydrochloric acid). Common, dissolves nylon, but polyester is resistant.

http://rfelektronik.se/manuals/Datasheets/solventguide.pdf
Hydrogen peroxide, or bleach might work too...

 

[Daniel in SD]

@ptbroderick, What ate the seatbelt thread? we need to know!

 

[ptbroderick]

@ptbroderick, What ate the seatbelt thread? we need to know!

Sorry, still waiting. It’s at the Tesla service center and they can’t figure it out. I will definitely update as soon as I know more

 

[skygraff]

Something venting out of the battery? Hope everybody's safe in your family and hope it's an isolated incident.

 

[ptbroderick]

They said it was definitely not from the car. Only thing I can figure is that I did leave a bottle of red wine in the trunk. Seems a tiny bit came out through the cork in these hot Georgia summers and leaked into the back of the rear seat. Makes you wonder about drinking red wine. It was a real nice bottle too!

 

[rodjpr]

I have a 2019 model 3, and have a similar problem with my rear center seat belt which will not pull out. Placing a Tesla service request.

 

[Jjmboni]

Well darnit! I was invested and there was no update! I think this thread got lost in the vacuum. I just happened across it because I'm having a different problem with my MX seatbelt and it came up in the search.

OP, did you ever find out what happened to your seatbelt?

 

[RayK]

Well darnit! I was invested and there was no update! I think this thread got lost in the vacuum. I just happened across it because I'm having a different problem with my MX seatbelt and it came up in the search.

OP, did you ever find out what happened to your seatbelt?

Post #32, two above yours, appears to be the last possible answer. OP has not been on this site since Jan 2021 so I doubt that you'll get an answer directly from them.