Issue with rear window when defroster on

[Koflach]

I turned my rear defroster on for the first time today and noticed that when it's on, the glass around the lines get's quite distorted. It doesn't look normal to me (as i've never seen this happen on any other cars in the past) and I wanted to see if anyone else has this happen to them.

If it makes any difference, I have the rear window that doesn't turn red anywhere on it.

 

[Koflach]

Here's a photo for reference. You can see that the car on the left and the house on the right are fairly distorted.

 

[DOCAL]

Do you have any tint on the window?

 

[Koflach]

Do you have any tint on the window?

nope

 

[LBU03]

Yea, i’ve noticed this as well. I wasn’t sure if the distortion was due to the moisture that was still in the windshield or not

 

[ebmcs03]

Humm never noticed. When i use the defroster it’s covered with dew anyways where I can’t see out the back window to even notice

 

[alseTrick]

That's...not ideal.

 

[Koflach]

That's...not ideal.

not in the least. Hopefully they will replace the back glass for me with one that's not defective.

 

[compu85]

If you look from the outside do you see lines in the moisture on the glass?

This is the way any defroster works, you're just noticing it more because of the direction changes on the Model 3's grid.

 

[LBU03]

If you look from the outside do you see lines in the moisture on the glass?

This is the way any defroster works, you're just noticing it more because of the direction changes on the Model 3's grid.

I think I understand what you’re saying here but this is not the issue that OP and I are seeing. I tested out the rear defroster again today with no moisture on the window (briefly). About 20-30 seconds after turning on, there was visible distortion created in the glass that was not previously there. Road lines seen through the rear windshield now had small curves at each point where the defrost grid lines crossed line of sight.

 

[LBU03]

I think I understand what you’re saying here but this is not the issue that OP and I are seeing. I tested out the rear defroster again today with no moisture on the window (briefly). About 20-30 seconds after turning on, there was visible distortion created in the glass that was not previously there. Road lines seen through the rear windshield now had small curves at each point where the defrost grid lines crossed line of sight.

OP’s pic doesn’t do a good job of illustrating the issue. I’ll try to get a before/after pic on my drive home.

 

[BobbyKings]

OP:

It's not the glass, it is the air that is unevenly heated and causes refraction.

Google on hot air refraction.

 

[GregRF]

Here's a photo for reference. You can see that the car on the left and the house on the right are fairly distorted.

Mine looks the same. Good reminder to turn it off once the window is clear... so a feature?

 

[BobbyKings]

Mine looks the same. Good reminder to turn it off once the window is clear... so a feature?

It's not the glass, it is the air that is unevenly heated and causes refraction.

Google on hot air refraction.

 

[Koflach]

they might want to look at turning down how hot the wires get which may cause less noticeable distortion. Yes, it would take a little longer to defrost/defog the window but it's a fair trade off for me.

 

[JohnC]

I have the same issue and scheduled an appointment to bring it in next week to get it looked at. I thought I can deal with it but after a while driving at night I start to get a little dizzy looking at the rear view.

 

[LBU03]

I have the same issue and scheduled an appointment to bring it in next week to get it looked at. I thought I can deal with it but after a while driving at night I start to get a little dizzy looking at the rear view.

Let us know what you hear from the SC

 

[Bandit]

Just adding that I noticed the same thing this morning. I don't think I'd be rushing to get it replaced until we know what's going on and if it matters. For now I'll manually turn it off once defogged.

 

[config.sys]

Many owners have reported this, but there isn't much that can be done about it based on post-repair feedback. What's weird is that not everyone is noticing it, so I think it's more than hot air refraction.

 

[ecarfan]

About 20-30 seconds after turning on, there was visible distortion created in the glass that was not previously there.

I do not see how the rear window defroster could “distort” the glass. The shape of the glass is not being altered by the heat produced by the defroster wires.

OP:
It's not the glass, it is the air that is unevenly heated and causes refraction.

Google on hot air refraction.

That is a reasonable explanation.

To those who think that replacing the rear window glass will effect this issue: I think that is very unlikely.

If you can’t see out the rear window because of moisture on the glass, turn on the defroster to get rid of the water and then turn it off as soon as it’s done it’s job. Don’t leave it on.