[ecdoesit]

While driving at along Route 15/501 (Chapel Hill) yesterday evening I heard a loud blast coming from my car, alarmed,I looked around my mirrors and saw nothing, but just then started hearing the wind on top of me...i did not see/ hear anything other than the strong blast. There was no debris on the road, no trucks, no overpasses. Nothing. I was shocked and confused, and couldn’t pull over my car to check for another minute at the next stop light. I believe the glass just spontaneously busted! Has anyone have any similar problems, heard of anything like this?

 

[markyp32]

Looks like something was dropped on your car from above.

 

[insightfully]

Haven't experienced this (EX)... but wow, good thing the sunshade was closed to prevent the debris from falling onto you!

The breakage pattern looks somewhat unusual; I'd think a more circular radial pattern would show up if it was damaged from an impact -? But maybe this is how tempered glass shatters when not laminated in the way a windshield is. Do you have extra tint applied to the moonroof?

Out of curiosity, I googled "spontaneous moonroof glass implosion" and was surprised at the number of articles/news on it. "The most common causes are minor damage during installation (e.g. nicked or chipped edges later developing into larger breaks), binding of the glass in its frame (e.g. stress from expansion/contraction), poor manufacturing quality (e.g. uneven distribution of air during cooling, contaminants, lighter/thinner weights)."
- This Consumer Reports article has two visuals showing incidents by manufacturer thru 2017. Hyundai has unusually high incidents; Honda is below-average in incidents. But the total number of incidents has been increasing annually (maybe because of broader use in cars?) and spiked in 2014.
- This ABC/GMA video shows types of damage from overhead impact and mentions the start of federal investigation in 2014/2015.
- And this video has brief tips at end for preventing heat-related implosion.

 

[Mr. Natural]

Spontaneous breakage can happen in all tempered glass. The thinner glass being used now days to cut weight doesn’t help. Edge damage is possible, but It’s just as likely a defect in the glass. I’d do a little research so I could talk smart to the dealer and try to get it replaced Under warranty.

 

[andrew28]

Looks like something was dropped on your car from above.

I was going to say the same but @ecdoesit said no overpasses. Also if something did drop, his picture doesn't seem to show the object, not sure if he found anything after cleaning up the glass.

 

[hasarad]

I was going to say the same but @ecdoesit said no overpasses. Also if something did drop, his picture doesn't seem to show the object, not sure if he found anything after cleaning up the glass.

If no overpass, what the **** did the bird have to eat???

 

[Wasabi]

Meteor!

 

[andrew28]

If no overpass, what the **** did the bird have to eat???

If it was a bird dropping, that is some incredible aim, right in the middle of the moonroof, while the vehicle is moving. :devil:

Meteor!

https://www.popularmechanics.com/space/deep-space/a9735/why-is-this-rock-worth-400000-dollars-16134667/
Might have been @ecdoesit lucky day if it was a rare one.:surprise:

 

[Mobilcams]

https://www.consumerreports.org/car-safety/exploding-sunroof-cases-head-to-court/

 

[Mr. Natural]

https://www.consumerreports.org/car-safety/exploding-sunroof-cases-head-to-court/

Good article! I also worked in glass manufacturing and witnessed countless spontaneous breakages of tempered glass. There was quite a bit of research done into the causes. One I remember was nickel sulfide inclusions in the raw glass.