Collecting Water: Overview of the problem
A problem discovered in late 2018 with the Tesla Model 3 rear bumper is that water pools and doesn’t drain from the rear bumper cover. The water can come either from being splashed up from the road surface while driving, or from rain or washing the vehicle – water drains down by the taillights and into the bumper cover.
This YouTube video shows how the water runs down behind the taillights and into the bumper cover:
https://www.youtube.com/watch?v=usdSDJTaEiw
There is much concern about what happens when too much weight gets in there, especially if the water freezes during winter and cannot drain out even when driving would typically allow water to ‘slosh’ around and find a way out.
Scooping Water: Overview of the problem
Parts of the underbody cladding of the Model 3 are made up of a semi-flexible, and tearable, composite material.
The piece located inbetween the rear wheels, covering the rear motor, has the front edge bolted up the the undercarriage which leaves the parts inbetween the bolts drooping slightly from the rest of the undercarriage.
If the Tesla is driven through enough water to start tearing/pulling the cladding down, it exposes the rear bumper to the same water.
Enough water, and the rear bumper cover is now a giant ladel scooping up all the water it can, until it tears the bumper cover right off.
History of the problem
In August 2018, a new Model 3 owner tweeted this. While bringing home his brand new Tesla Model 3 and encountering heavy rain in the street, his rear bumper was pulled off:
https://twitter.com/rithesh/status/1028437449318576128
He received a response from another Model 3 missing his rear bumper, because of driving through some standing water
https://twitter.com/Benj1Franks/status/1028459288799465473
Tesla’s official response:
We’re setting an extremely high bar for Model 3, and what happened in this situation is not how we build our cars. We’re investigating the issue to understand what caused it, and we are contacting our customers to resolve this and ensure they are satisfied.
August 2018 – a thread was started to record VINs of the Tesla Model 3s that lose their back bumper.
In October 2018, forum member CDHowe posted about the rear motor cover dragging on the ground after driving around in heavy rain
The Tesla Service Center was ordering a part to replace the torn one.
In October 2018, Forum user SnickSnacks posted pictures of his torn undercarriage panels after just 2 and a half weeks of owning the Model 3:
According to SnickySnacks, his Tesla Repair Center is claiming that it is normal wear and tear and they won’t cover it. Specifically, they claim that he went through high water too fast. Other forum owners reported having theirs fixed as a courtesy.
One owner wanted it fixed, so he paid for the part plus labor and it cost $150 at the service center. “I’ll be going through puddles at 1mph from now on”
Sources/Threads with details
August 2018 – Jalopnik – Bumper falls off of Brand New Tesla after 30 minutes of driving
August 2018 – Tesla Motors Club – VINs of cars who lost back bumper cover?
October 2018 – Tesla Motors Club – Weird Rain Damage
October 2018 – Tesla Motors Club – Ripped Undercarriage Composite from the rain
November 2018 – Tesla Motors Club – Found out what’s causing undercarriage composite to break apart