Rear window explosion

Howdy Folks

Quick search didn't come up with anything on this, so figured I'd post

My wife was warming up our 2004 Vue (FWD 4-cyl), got in, started the
heater going, and when she closed the door, just a few seconds later,
she heard a pop - the rear window had shattered out (from the inside).

This is obviously an internal pressure issue, but in my experience,
cars should always have some form of vent to release the pressure
inside the cabin. My Jeep has these vents in the rear quarter panels.
I wonder if Saturn puts them lower on the vehicle? Perhaps in an area
prone to splashback?

We're in Colorado, and we've had a pretty good cold snap this week. It
was probably -2 Farenheit when the explosion happened.

Any insight on this? Should I perhaps try to get some kind of warranty
reimbursement for it, and also have them figure out why the pressure
wasn't released? Is this common at all, or am I just "lucky"?

Thanks in advance

Jim Karlin
Denver, CO

 

Did she turn on the heated backglass? My dad had this happen many
years ago in a Honda Accord. The insurance paid for the broken glass,
less the deductible. Then Honda came through with a recall and
reimbursed for the deductible since the glass had already been
replaced. The recall specified that the dealer stick some strips of
sticky copper strips along the sides of the glass to better distribute
current across the glass, reducing hot spots.

RK Henry

 

As many will no doubt say, it was certainly not air pressure that broke
the window. It would not be possible for the heater fan to develop that
much pressure, with or without vents.

All glass in a car, except for the windshield, is made of tempered
glass. The glass is highly stressed so that if it breaks it will
crumble into many little pieces, rather than long dangerous shards.
While this glass is reasonably resistant to impact on its face, it is
very sensitive to thermal stress (as another poster pointed out) or to
stress applied to the edges.

I would favor the theory of uneven heat from the rear defroster, if that
was turned on. It is possible that an installation problem might have
allowed the edge of glass to contact the metal frame of the window,
transferring a shock to the edge of the glass. I have no experience
with that, its just a guess.

FYI: Windshields are not tempered, because failure would either prevent
you from seeing, if the glass shattered but did not fall out, or the
pieces might end up in your eyes, if they did fall out. Instead, a
windshield is made from two sheets of glass with a clear goop of some
kind between them, so that if it breaks you have a cracked sheet or
sheets of glass that you can still see through, but is flexible and that
does not fall apart.

--
NOTE: to reply, remove all punctuation from email name field

Ned Forrester 508-289-2226
Applied Ocean Physics and Engineering Dept.
Oceanographic Systems Lab http://adcp.whoi.edu/
Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA

 

I agree - IMO it's not air pressure, but the temperature. Still should not
have done that and the fact that you don't hear about it more often (as
there are plenty of Vue's operating in that temperature or colder) leads me
to think that it was probably a defect in the glass or in the installation
of the glass. It may even be a minor, visually unnoticeable defect in the
frame for the glass. I would definitely go the route of getting it fixed
through warranty. It can't hurt, although it will be damn cold on your
drive over to the dealer!

The other thing is by doing that, at least if it does it again, Saturn will
have it on record that they did the repair before. You may have an argument
to have them fix it again even if the car is out of warranty at that time.

Scott

 

I don't have anything to help here, just a couple of anecdotes that
indicate auto glass can be fragile.
I had a rear window shatter on a parked '74 Gremlin when a strong gust
of wind lifted it up and slammed it.
This past November, a week after Holloween, somebody driving past in a
car tossed a dead pumpkin at my parked '04 Vue's rear window and
shattered it. Crumbled glass ended up throughout the interior, all the
way up to the dashboard. I'm still cleaning up bits of glass from
nooks and crannies. This might be funny, except that the repair cost
$600.

 

The glass on my father's 1957 Ford wagon broke into tiny pieces and stayed
intact in the frame for a few days. It was open and parked and the sun must
have hit it just right for a while. Thermal stress was the only
explanation. I was a young lad at the time.

 

It's not common but it happens. My dad's honda minivan had one window
just go boom suddenly one day, though we suspected it got pegged by a
rock from the weedwacker, but never confirmed it. car windows have been
known to spontaniously go boom for whatever reason. Happens to all
cars...

 

I'd say the glass was installed in a bind or improperly cushioned. The
internal pressure had nothing to do with it. The most pressure there is is
when you slam the door. And they don't blow out then.

 

Thank you all for the responses and insight. Since the Vue is my
wife's car and my 22 month-old daughter rides in it as well, we had
insurance cover the repair. Should I call the dealership we purchased
the vehicle from to report the issue, or should I go straight to
Saturn? I'm not overly concerned with having my deductible reimbursed
(would be nice, but I'm not losing any sleep over it, nor will I hold
my breath), but I wonder if there is a similar issue to what RK saw
with Honda. Other owners deserve to know if there's an issue with the
defroster.

Thanks again

Jim

 

My guess is if the insurance industry sees a trend, they will bitch.

 

I think you've hit the nail on the head, probably due to faulty
installation. The glass expanded, something blocked it's movement and
KABOOM. I've hear anecdotes about this happening. Since it's likely a
manufacturing defect, it should logically be covered under warranty. I don't
know how stinky Saturn is about claims these days . When I got my '96 they
were very generous, but times change.

As far as air pressure is concerned, a car is well vented. If it wasn't, you
wouldn't get much air flow through the vehicle when using the heater, AC, or
fresh air ventilation. Plus you'd likely get a lot of condensation on your
windows. So the car has to be a sieve for air.

 

You can most likely throw faulty installation out the window. The rear
window isnt mounted like that anyways. It is a not so common thing for car
windows to break in or out due to extreme heat / cold exposure as you
described. Think about it: -2 F outside, rear window defroster heating the
glass, heater inside, the temp inside of the vehicle is many degrees hotter
than the frozen outside. Now throw in slamming the door. It would not take
much pressure of the door closing for the window which is hot on one side
and frozen on the other to cause the glass to weaken and "explode".



marx404