Undercoating in Model 3, Don't do it!

[ben1628]

From the warranty section, I didn't know that:


Body Rust Limited Warranty


This Body Rust Limited Warranty covers rust perforation (hole through the body panel from the

inside outwards) resulting from a defect in material or workmanship for a period of 12 years and

unlimited miles, excluding the following:

• Vehicles treated against rust, i.e., procedures commonly referred to as rustproofing or


undercoating;

• Corrosion from defects in non-Tesla manufactured or supplied materials or workmanship

causing perforation in body panels or the chassis from the inside out;

• Surface or cosmetic corrosion causing perforation in body panels or the chassis from the

outside in, such as stone chips or scratches;

• Corrosion caused by, due to, or resulting from accidents, abuse, neglect, improper

maintenance or operation of the vehicle, installation of an accessory, exposure to chemical

substances, or damages resulting from an act of God or nature, fire, or improper storage.


For more information on other paint, rust or corrosion concerns that are excluded from this New

 

[puzz1ed]

exposure to chemical substances

So anywhere they use salt on roads they don't cover it?

 

[ben1628]

What page in the owner's manual did you see this, or is this within the car's menu? I can't seem to find it.

In the owner manual under your tesla account. I think it may be something new as people reported back in 2018 that there was no rust warranty.

12 years and unlimited mileage.

 

[Techniques]

In the owner manual under your tesla account. I think it may be something new as people reported back in 2018 that there was no rust warranty.

12 years and unlimited mileage.

I contacted executive support when I first got my car asking for clarification on rust proofing. This is nice to see the warranty being clearly stated.

 

[ewoodrick]

Why would one spray plastic on a big piece of plastic?

 

[Lasairfion]

Same reason why people spray stuff over the paintwork etc. I've always seen paint as a protective coating for the metal, personally.

 

[JasontheBeaver]

This is a great thread topic!
We've been spraying undercoating since 1995, but back then it was primarily to combat corrosion on floor pans and inner fenders that were more exposed to the elements and usually just had thin primer on them from the factory.
Nowadays most vehicle manufacturers warranty their cars against corrosion for a much longer time because they're using more corrosion resistant metals, more plastics, more aluminum, and protecting the most vulnerable components.
The reason Tesla is excluding undercoated cars is because if done improperly, the undercoating's adhesion can start to fail and allow pockets to form that will hold moisture and chemicals (salt) against the surface permanently thereby increasing chances of corrosion.
In my Model 3 undercarriage inspection video you can see that there is no reason to undercoat that vehicle because there's no exposed and vulnerable steel that could be reasonably accessed and protected with undercoating. The metal under-tray is fairly thick so even if the paint gets scuffed off during normal driving it's just not going to corrode to a level of any concern for a very long time.

Another reason people get undercoating is for sound-deadening but again nowadays this is pretty much worthless on modern cars due to their designs. In much older cars we could cut down on road noise with undercoating because the floor pans resonated and transmitted a lot of noise. A thick coat of asphalt based rubberized undercoating helped stop the vibration and quieted things down a bit. Modern cars are built much differently so to eliminate road noise we must approach it in a much different way.

 

[03DSG]

From the warranty section, I didn't know that:


Body Rust Limited Warranty


This Body Rust Limited Warranty covers rust perforation (hole through the body panel from the

inside outwards) resulting from a defect in material or workmanship for a period of 12 years and

unlimited miles, excluding the following:

• Vehicles treated against rust, i.e., procedures commonly referred to as rustproofing or


undercoating;

• Corrosion from defects in non-Tesla manufactured or supplied materials or workmanship

causing perforation in body panels or the chassis from the inside out;

• Surface or cosmetic corrosion causing perforation in body panels or the chassis from the

outside in, such as stone chips or scratches;

• Corrosion caused by, due to, or resulting from accidents, abuse, neglect, improper

maintenance or operation of the vehicle, installation of an accessory, exposure to chemical

substances, or damages resulting from an act of God or nature, fire, or improper storage.


For more information on other paint, rust or corrosion concerns that are excluded from this New

Good catch Ben. This is new as of Feb 1, 2019 warranty manual. More important for the 3 than the S and X due to the 3’s steel content.

 

[shellderp]

Don't expect much from rust warranties. Carmakers will make any excuse possible to not honor it and make it a pain in the ass for you to use it

 

[navguy12]

Don't expect much from rust warranties. Carmakers will make any excuse possible to not honor it and make it a pain in the ass for you to use it

Like "stone chip" surface corrosion. ......check out anybody with a TM3 with a Canadian winter under thier belt, check the rockers, especially aft of the front wheel wells.

I sprayed Rust Check spray last June into all the chassis, under the frunk, under the trim of the trunk, inside the rear trunk lid, etc.

Stuff is still weeping out (as it is designed to do) from places like the painted body mastic line around the top of the rear license plate area, where the door hinges are attached to the body, etc.

Also, when I bought the car last spring, there was no specific corrosion exclusion that mentioned rust proofing (actually no real corrosion warrenty at all).

 

[mswlogo]

So anywhere they use salt on roads they don't cover it?

Hopefully that's not what they are referring too.

 

[Goodtohave]

Don't expect much from rust warranties. Carmakers will make any excuse possible to not honor it and make it a pain in the ass for you to use it

Surprisingly I bought my used 2008 BMW wagon 2 yrs ago, there was rust on the underside of the tailgate. BMW replaced the hatch and painted it no charge.

No hassle at all.

 

[ben1628]

Good catch Ben. This is new as of Feb 1, 2019 warranty manual. More important for the 3 than the S and X due to the 3’s steel content.

I was looking for the user manual for something else, and then the rust warranty catch my eyes. Yes, must be something new.

 

[ben1628]

Don't expect much from rust warranties. Carmakers will make any excuse possible to not honor it and make it a pain in the ass for you to use it

That section wasn't there before. Now they put it in, it will at least means that they are comfortable with the rust protection in M3 now. Whether you can claim it or not will certainly depending on the circumstances. If there is no rust warranty at all (like before), they won't even entertain the idea.

 

[duanra]

resulting from a defect in material or workmanshift. So normal rust is not covered ;-)
Anyhow, I would rust proof it by a reputable outfit. I live in Quebec and winter is brutal for the car. Without rustproofing corrosion is a lost battle.

 

[Goodtohave]

My experience with model 3’s shows they will rust from the outside, the rockers and lower body is very exposed and gets chipped and sandblasted. This is not covered under the warranty.

Ppf is the way to go. Doors are aluminum which is the common rust spots on most cars.

I sprayed every car every year up until my last car.

Now I just keep a can of Crown undercoating and spray the exposed metal bits near the suspension etc when it’s up on a lift.

Cars used to rust after 5 years. Now it is after 10 years.

Undercoating won’t help, it will probably just trap moisture in all the dirt and oil.

Certainly not going to void a warranty for it.

 

[Marsontherocks]

My experience with model 3’s shows they will rust from the outside, the rockers and lower body is very exposed and gets chipped and sandblasted. This is not covered under the warranty.

Ppf is the way to go. Doors are aluminum which is the common rust spots on most cars.

I sprayed every car every year up until my last car.

Now I just keep a can of Crown undercoating and spray the exposed metal bits near the suspension etc when it’s up on a lift.

Cars used to rust after 5 years. Now it is after 10 years.

Undercoating won’t help, it will probably just trap moisture in all the dirt and oil.

Certainly not going to void a warranty for it.

But aren't exactly the doors on the Model 3 steel?

 

[Marsontherocks]

My experience with model 3’s shows they will rust from the outside, the rockers and lower body is very exposed and gets chipped and sandblasted. This is not covered under the warranty.

Ppf is the way to go. Doors are aluminum which is the common rust spots on most cars.

I sprayed every car every year up until my last car.

Now I just keep a can of Crown undercoating and spray the exposed metal bits near the suspension etc when it’s up on a lift.

Cars used to rust after 5 years. Now it is after 10 years.

Undercoating won’t help, it will probably just trap moisture in all the dirt and oil.

Certainly not going to void a warranty for it.

I thought for sure the doors were steel though on the Model 3.

 

[navguy12]

I thought for sure the doors were steel though on the Model 3.

Try a magnet to satisfy your curiosity.

A magnet will not stick to the hood or the four doors.

 

[duanra]

Try a magnet to satisfy your curiosity.

A magnet will not stick to the hood or the four doors.

But it will stick on the rocker panels.