Windscreen crack this morning after defrosting

[rowedav]

I've had my M3P just under a year and this is the first real issue I've had. So basically, we've had cold temperatures and snow here in the North East the last few days. I've always used the defrost mode on the app the de-ice the car before using the car without issue. Did the same again this morning as had a good inch or so of snow overnight and settled on the car. 5mins after leaving, I get a call from the missus saying there's a crack at the bottom of the windscreen in the middle.

Is it possible the inside heat vs the outside temp has caused the glass to crack? I'm sure I've read similar stories about this before. Obviously I need to take a close look tonight when the car returns to see if there's any sign of a stone impact.

If it is a crack that seems to have appears with no sign of impact - is that something I can get corrected under warranty?

 

[ScottNY]

I melted snow off my windshield using the defroster at 80° last winter. I woke up to a 20” long crack along the bottom of the windshield with absolutely no sign of impact damage. Brought it to the Tesla SC and it was replaced free of charge right there in the shop. Now I defrost at a much lower temperature. So far, so good.

 

[ringi]

Sounds like it needs a software change to limit temperature when cold outside for long enough to allow the glass to slowly worm up.

 

[ThunderBay3Y]

I had this issue, Northern Ontario Canada here, absolutely no sign of any impact. Put the defroster on one -2C morning and when my wife went to her car she saw it was cracked. I put in for a service request and the mobile ranger came and was able to assess it and confirmed it was not an impact and was covered by warranty (I don't live near a service center to just have it looked it). My only concern was that it was months before they could come, it ended up spreading and cracked across the entire back window by then (looked like a smile) but I submitted a picture of it at the time of the service request - they were fine with it.

Cracked Rear Window

So its only -2C here which is not very cold for March in Northern Ontario. Our M3LR started preconditioning on schedule for 730am depart. When my wife got into the nice and toasty warm car she observed that the rear window was cracked from around the rear defrost lines down to the bottom of...

teslamotorsclub.com

 

[Sean.]

I've had my M3P just under a year and this is the first real issue I've had. So basically, we've had cold temperatures and snow here in the North East the last few days. I've always used the defrost mode on the app the de-ice the car before using the car without issue. Did the same again this morning as had a good inch or so of snow overnight and settled on the car. 5mins after leaving, I get a call from the missus saying there's a crack at the bottom of the windscreen in the middle.

Is it possible the inside heat vs the outside temp has caused the glass to crack? I'm sure I've read similar stories about this before. Obviously I need to take a close look tonight when the car returns to see if there's any sign of a stone impact.

If it is a crack that seems to have appears with no sign of impact - is that something I can get corrected under warranty?

When I had this happen on our model X it was an existing chip that caused the crack - an amazing crack at that too.

There could have been an imperfection or other damage to the edges of the screen on original install too. Not otherwise visible.

 

[Drew57]

I recall seeing posts about the results of excessive heat on Tesla glass during the first winter I owned a Tesla so since then I use the app to set climate to around 24º C and make sure a/c is disabled. This warms the car slowly & normally achieves the desired result without risk of cracking.

Having said that, we returned home Wednesday night from 6 weeks overseas and the car was literally a solid white block of ice complete with frozen icicles on every overhang. The interior defrosted OK after 15 minutes including the windows and it looked OK to enter the car but as soon as I punched the handle & opened the drivers door the glass remained frozen shut and didn't drop (I foolishly hadn't applied Gummi Pfledge yet this winter). To avoid the door frame shattering the glass it was left slightly ajar with the heating on while I got a hairdryer/extension lead to gently warm the bottom edge of each window to melt the ice. Then they all dropped as normal.

Defrosting the car and windows used 4% SOC but I wasn't going to take any chances & I now have an old hairdryer in the boot in case the same happens when I'm away from home.

 

[MrBadger]

Defrosting the car and windows used 4% SOC but I wasn't going to take any chances & I now have an old hairdryer in the boot in case the same happens when I'm away from home.

How do you get in the boot if that’s frozen…

Just asking from recent experience. Even with Gummy Pfledge I normally find that and front are the first to freeze as they don’t receive any cabin heat, at least not in Model 3. Running hand along top edge of boot might be enough sometimes.

 

[Drew57]

How do you get in the boot if that’s frozen…

Because my current Tesla is a Model Y, the heat more easily percolates throughout & this opened without issue after warming the cabin. I don't recall an issue when I had a Model 3 but never had a very cold snap when returning from overseas so maybe that could have been a different result.

 

[rowedav]

Thanks for the replies. First time since posting I’ve been on the forums so a bit of an update.

I inspected the car when the Wife got home on Friday and sure enough there is an impact point further down so looks like a stone chip has caused it initially (not sure when this happened but must have been recently) and then the temperature and heating has caused it to expand/crack.

Gone through insurance as a result and have £115 excess to pay.

Interesting to hear other have had issues from the defrosting before though.

 

[Dangerous Fish]

Thermal shock will do this and as said any small imperfection can be where it starts. Whether warranty or insurance covers it will probably just be down to how each service centre approaches the claim. The same has happened with the rear screens with heating elements a fair bit in the past but I believe there may have been a manufacturing defect with a lot of those, so probably more went through warranty.

If anyone's really concerned It may happen to them, it may be better not to use the defrost mode initially but rather condition earlier at say 25 degrees with all the heated seats on so the inside of the glass warms up more gradually.

It can also happen during hot weather. I had a BMW windscreen crack when I sprayed it with cold water in a heat wave. Annoying but lesson learnt.

 

[Sean.]

I inspected the car when the Wife got home on Friday and sure enough there is an impact point further down so looks like a stone chip has caused it initially (not sure when this happened but must have been recently) and then the temperature and heating has caused it to expand/crack.

That will be it. Once it’s weakened a sharp temperature change, like a defrosting cycle, will be enough to crack it