Pressure crack on Windshield at -16F

[twodogsdennis]

Temps over the weekend got to -16F, which is not that cold depending on where you live. I turned on preconditioning Monday evening and went out ten minutes later to clean the windshield of about 3" of snow and ice in preparation of a 7:30am departure on Tuesday. On Tuesday morning, I again turned on preconditioning at 7:00am. Well, as I was leaving, I discovered a pressure crack across the bottom of the windshield. The crack is about 3" in the middle and 4"-6" above the bottom of the glass on either side. This has been a concern of mine for some time as the preconditioning temp set at warm seems to do a great job of warming the windshield until it creates a problem. I've tried looking to see if the temp or direction of air can be adjusted but haven't found anything other than the "warm or hot" settings. I've had this problem before on other trucks and cars, sometimes in the summer or winter here on the front range of Colorado. When temps drop and the sun comes out, glass occasionally doesn't respond well. Any advice from the Canadians, northern states, or Gunnison and Grand Valleys of CO, where I'm sure the temps are even colder on the trucks that park outside and are connected to shore power?

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[RickLightning]

Ford covers stress cracks for 12 months / 12,000 miles. With all the glass on these vehicles (and my Mach-E), I have zero deductible glass. Mach-E got its 2nd windshield (rock) in July or August, and its 3rd this month.

 

[twodogsdennis]

Ford covers stress cracks for 12 months / 12,000 miles. With all the glass on these vehicles (and my Mach-E), I have zero deductible glass. Mach-E got its 2nd windshield (rock) in July or August, and its 3rd this month.

Thanks for the info. At the time of purchase, the dealer wanted an arm and a leg for glass coverage, so I stuck with the glass coverage on my personal policy.

 

[RickLightning]

Thanks for the info. At the time of purchase, the dealer wanted an arm and a leg for glass coverage, so I stuck with the glass coverage on my personal policy.

That's what I have also. To go from the regular deductible to zero is $175 for total for both vehicles. A windshield, with recalibration, is like $1,800. Roof is like $2,500...

 

[paulcusick3]

I got same crack this week on my 22. In MA it is covered by insurance. I made the rookie mistake of putting max defrost on with ice and snow.... the temperature differential is a receipt for this. I take the blame.

 

[Heliian]

It's not the heat or the preheating or the snow on the windshield.

Yes, the windshield will expand and contract but that alone doesn't cause cracks. Cracks are usually caused by existing damage like a stone chip, even a very small stone chip that you won't notice will eventually crack when it's cycled enough times.

That's why it's important to fix stone chips if you don't want your windshield cracking. Personally, I never have them fixed and run the windshield until a crack becomes problematic, ie in the line of sight. After about 5 years of driving around these parts, the windshield gets so sandblasted that light reflects poorly and you can't see out of it anyways.

Windshields are consumable items Imo, make sure you've got good glass coverage ON YOUR INSURANCE.

 

[twodogsdennis]

It's not the heat or the preheating or the snow on the windshield.

Yes, the windshield will expand and contract but that alone doesn't cause cracks. Cracks are usually caused by existing damage like a stone chip, even a very small stone chip that you won't notice will eventually crack when it's cycled enough times.

That's why it's important to fix stone chips if you don't want your windshield cracking. Personally, I never have them fixed and run the windshield until a crack becomes problematic, ie in the line of sight. After about 5 years of driving around these parts, the windshield gets so sandblasted that light reflects poorly and you can't see out of it anyways.

Windshields are consumable items Imo, make sure you've got good glass coverage ON YOUR INSURANCE.

Thanks for the reply. If indeed this was a stone chip, it was microscopic and at the bottom of the windshield. Like you, I don't fix the chips on the Silverado since often the cost to repair is half the price of the replacement windshield that my ICE mechanic shop charges. Safelight gave me a chip quote last time and I just laughed. Since buying the Lightning, the miles have been limited on the Chevy and in turn is keeping that windshield chip free. haha!

 

[paulcusick3]

I had a small chip where it started, yes

 

[Firn]

It's not the heat or the preheating or the snow on the windshield.

Yes, the windshield will expand and contract but that alone doesn't cause cracks. Cracks are usually caused by existing damage like a stone chip, even a very small stone chip that you won't notice will eventually crack when it's cycled enough times.

That's why it's important to fix stone chips if you don't want your windshield cracking. Personally, I never have them fixed and run the windshield until a crack becomes problematic, ie in the line of sight. After about 5 years of driving around these parts, the windshield gets so sandblasted that light reflects poorly and you can't see out of it anyways.

Windshields are consumable items Imo, make sure you've got good glass coverage ON YOUR INSURANCE.

High heat on a cold windshield is well know to cause cracking. The issue isn't expanding or contracting, its that one area is hot and expanding and the rest is cold and NOT. This also applies to the layers of glass too, with the inside layer being hotter than the outside layers.

FWIW I was once told to circle a chip in the windshield with a #2 pencil and it will stop it from spreading. Makes no sense to me, but i have not had a chip spread either. Does it work? who knows, but its essentially free and dang easy to do, and if I ever have a chip spread I'll stop doing it.

 

[Heliian]

High heat on a cold windshield is well know to cause cracking.

The heat generated by any of my vehicles in the last 29 years has never caused a crack. It was - 30 deg C here yesterday and preheating didn't cause any cracks. It's entirely possible but highly improbable that an intact windshield will crack. My truck lives outside and is covered in snow and ice all winter.

I found the worse places for windshields are jurisdictions that use gravel on the roads in winter. BC was notorious for that, Ontario uses mostly sand, hence the sandblasting.

 

[Firn]

The heat generated by any of my vehicles in the last 29 years has never caused a crack. It was - 30 deg C here yesterday and preheating didn't cause any cracks. It's entirely possible but highly improbable that an intact windshield will crack. My truck lives outside and is covered in snow and ice all winter.

I found the worse places for windshields are jurisdictions that use gravel on the roads in winter. BC was notorious for that, Ontario uses mostly sand, hence the sandblasting.

I don't live in the frozen wilds anymore, but I used to.

I have had it happen to me, and OP had it happen to him. Just because it didn't happen to you, or does not happen every time, does not mean it does not ever happen.

The only time a windshield is perfect is before it's installed. But that does not mean there was a chip there when it cracked. It also does jot mean heat was not the cause of the crack.

 

[RickLightning]

Thanks for the reply. If indeed this was a stone chip, it was microscopic and at the bottom of the windshield. Like you, I don't fix the chips on the Silverado since often the cost to repair is half the price of the replacement windshield that my ICE mechanic shop charges. Safelight gave me a chip quote last time and I just laughed. Since buying the Lightning, the miles have been limited on the Chevy and in turn is keeping that windshield chip free. haha!

My insurance has free crack repairs, because they want to avoid replacing windshields.

 

[VermontEagle]

I got same crack this week on my 22. In MA it is covered by insurance. I made the rookie mistake of putting max defrost on with ice and snow.... the temperature differential is a receipt for this. I take the blame.

I’m just north of you in VT. I didn’t have any preexisting damage to the glass. I entered my truck yesterday after turning on the cabin preheat to find a crack approximately 24” long in all. The crack is in the shape of a smiley face of all things, with the bottom inches above the dash. I can’t imagine that the low/high temperature difference wasn’t the cause.

I bought the truck over the summer. The high preheat was the default setting that I’ve used all winter. Using it shouldn’t be a “rookie mistake.” They have F-150’s all across the snow belt and the glass should be made to withstand such temperatures.

 

[paulcusick3]

I’m just north of you in VT. I didn’t have any preexisting damage to the glass. I entered my truck yesterday after turning on the cabin preheat to find a crack approximately 24” long in all. The crack is in the shape of a smiley face of all things, with the bottom inches above the dash. I can’t imagine that the low/high temperature difference wasn’t the cause.

I bought the truck over the summer. The high preheat was the default setting that I’ve used all winter. Using it shouldn’t be a “rookie mistake.” They have F-150’s all across the snow belt and the glass should be made to withstand such temperatures.

I had a very small crack right next to ford stamp in the middle bottom. I only knew it was there because I heard it when it happened. It did not grow at all, until I had ice and snow and now is 3-4 feet.

 

[RickLightning]

Glass gets very brittle in cold weather. I heard my latest stone hit, and should have more carefully checked things. The hit was below the wiper on the Mach-E, way down. MIGHT have been fixable. Then, it wasn't...

Stress cracks happen, which is why Ford covers it for 12 months. After that, that's what insurance is for.

I strongly recommend to my friends to get $0 deductible glass coverage, especially when the vehicle has a glass roof as both mine do. The Mach-E glass roof is something like $2,500 I think.

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