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Mysterious Windshield Crack

Hello, everyone. I’ve seen another thread here about mysterious windshield cracks, but not one for a new(ish … 1 yo) car. I can’t find any impact mark, the cracks don’t center on any single spot, and are at the very bottom of the windshield (mostly protected by the wipers and top of the hood). I can’t feel any discontinuity in the glass as I run my fingernail along/across the exterior.

Could this be a heat stress issue? I’m thinking this is a warranty problem, but fully expect the dealer/automaker to deny responsibility…I’m not thrilled about calling my insurance company.

No it is not. Why have insurance if you are not going to use it ? Call your insurance and get the details. Then decide to make a claim or not.

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Can you explain why you view it this way?

If this is not related to impact - which there’s no evidence to suggest that it is - why wouldn’t this be VW’s responsibility?

OK, pickup the phone and call the service department and get the answer.

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Because there are many cracked windows caused by an impact that show no signs of an impact. I’ve had them.
There was when the impact first happened…but then the crack started and the impact disappeared.

As for Heat Stress? Not likely. Cars in South America would be having them all the time…and they don’t.

Your windshield can be replace under warranty for a stress crack. In some cases the layer of urethane between the glass and body is too thin, the body can be touching the glass and eventually cause it to crack.

Stop by your dealer for an inspection, it won’t cost you anything to ask.

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There was a spate of windshield cracks in Toyota Previas - some problem in design, manufacturing processes, body flex, etc. It is possible VW has a role in this, and may fix it.

Stop by the dealership and let them look at it and tell you if it’s covered by the warranty.
If not, call your insurance agent. Some insurers in some states will cover cracked windshield replacement 100% without any accident involved. It’s free to ask.


Can you reach the interior where the crack is? If the crack is in the inside layer, you’d have a stronger case for warranty coverage.

Glass cracks, sometimes you know why, sometimes you don’t. There is no way any manufacturer is going to guarantee glass. If it is a new car you must have comprehensive. Most people have full glass coverage.
There are big differences in the quality of replacement window glass. Educate yourself before you get it replaced.


I had a windshield replaced about 2 years ago. Comprehensive insurance covered 100%.


That is a good reason to visit the dealer first, for warranty repairs we must use genuine OEM glass.

I had a rock chip my windshield in the drivers field of vision. My insurance company had a glass company come to my house to fix it. I have a $50 deductible, the glass company had a ‘coupon’ for $50 so I had no out of pocket. The work was excellent.

Hard to tell what may have caused your crack. @the_same_mountainbik has good advice, head on over to the dealer to look at it, if they cover it great, if not see your insurance company.


There is no reason to assume, just because you can’t find an impact mark, that the crack wasn’t caused by an impact that didn’t leave a mark (other than the crack).

This isn’t some great mystery that you need to solve and find the cause. You have a cracked windshield, and in several states (where driving with a cracked windshield is illegal), insurance companies are required to replace windshields with no deductible. I recommend you get it fixed and stop obsessing about the possible cause. It isn’t going to make your premiums go up to file a claim with your insurance company. In fact, if your insurance agent is like mine, he/she will appreciate that you’re taking care of this rather than driving around with a cracked windshield.


The OP could have called the service department and the insurance company in less time then it took to search and log on.

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An improperly installed windshield at the manufacturer could indeed crack later. I don’t see any bulletins about it for this car, but good advise above to take it to the dealership and ask them to take a look. They might be able to spot what caused it just by looking. It’s a fairly complicated thing to install a windshield, not rocket science, but it has to be done int he correct sequence and using the right parts. And it has to be done carefully so the rubber moldings around the perimeter of the windshield mate up correctly with the edge of the window and the thing they mate to on the car, to do their job of both protecting the glass from stress fractures as well as keeping it watertight. Contrary to some comments above, this isn’t something that can be evaluated over the phone.

What parts? Most windshields are glued on.

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All modern car windshields are bonded on and form an integral part of the crash protection system as well as the unibody integrity (strength). George is correct in that they must be bonded on properly to do their jobs correctly. Any reputable automotive glass business has the tools and expertise to do so properly… even right in your own driveway (weather permitting… there are ambient temperature limits). It isn’t rocket science, but it does need to be done right.


Windshields – in the past anyway – used to be held in place with a sort of rubber gasket. One side matched up with a flange that ran around the entire windshield opening, and the other side had a channel sized for the glass. So there was a rubber cushion holding the windshield in place, providing a buffer to allow the glass to expand and contact against. Often a glue or sealant was used along with the gasket. There were often other trim piece gadgets involved besides the gasket. It’s sort of trick how they install that gasket. I think they use rope or strings or something like that. Have they stopped using the gasket in new cars now? Only glue?

Yup, they’ve stopped using the gaskets now.
They’re using the windshield itself as a structural component now, even designing airbags to use the windshield as a surface to expand against.

The old rubber gasketed windshields required a strong cord, a couple of handles to pull on, and a bit of technique to replace. It wasn’t rocket science, but even then it was often best left to someone with some practice. A practiced windshield guy could do it in minutes, a novice could waste an entire afternoon.