AX993

I did a forum search, but I guess it's broken. Has anyone had a rear window explode without being hit by something?? I had driven over 300 miles today to Cal Turner's BBQ and Tubs meeting near Nashville, Came home and rested for about 3 hours, Pulled the car back out of garage to rinse the bug guts and dust off the car with water(while letting the engine warm up), then drove to local gas station to fill up the gas tank. As I was pulling out of the gas station, I hear a loud bang from behind me. I look back and see the rear window glass, while still in place, is totally broken up into small bits. I pull over into a parking lot to see what hit me, but there is no indication of an impact of any kind.
The particulars: 1996 narrow-body with 17" wheels, about 63,000 miles, I do have PSS9 suspension but it's set near the middle of firmness. A PO put in window tint film. The glass is still in the frame ( I guess the window tint film is holding it together from the inside), but was still making cracking noises when I got home.
Anyone have any experience with something like this?? Or how much this is gonna cost to fix?
TIA, Glenn

gordo993

I've heard of chassis flex breaking front and rear glass on WRX's (my daily driver), but I haven't heard of this phenomenon occuring with the Porsches. Did you hit a bump? come down off a driveway? flex the chassis in any way?

The Brewmeister

Sounds odd. Do you think it may have taken a shot from a pellet or BB gun?
side and rear glass is designed to shatter into small pieces in an accident.
All it takes is an impact just the right way to break the entire thing. A snap
from a spring loaded machinist's center punch will often do in tempered
glass windows.

cnrfan

Wasnt this a problem on a few early 1995 models? I'm with brewmeister, probably some idiot kid with a pellet gun.

AX993

Gordo993, I was just leaving the gas station, no bump or unusual flex. Lots more bumps and rough roads on the 300 miles earlier in the day and no problems. Brewmeister and Cnrfan, I'll look closer at the glass tomorrow in better light, but I didn't see any sign of a bb or pellet hit tonight. The way the glass is all in small bits, I'm not sure I'll be able to tell though. Maybe I'll see something in the daylight.
Glenn

CAHRERA

Just did a search on it. And it seems it could be caused by rear window defroster wiring in the glass or the wiring of the 3rd brake light mounted on the top of the rear window. And it seems to have happened to those with 95 and 96 modeled cars.

C4SJOHN

I had that happen about a year and a half ago on my 1996 C4S. I was told that the car was too air tight and that I needed to crack the door windows every time that I could. By opening and closing the doors with the window roll up all the way the back window is like a drum skin it bounce out and back and gets weak over the years then brakes. It was hard to find a replacement window the dealers and Porcshe North America had no stock and the factory would have to place a order to manufacture some new rear windows. I ended up getting one from a friend that was changing his car into a race car and removed the glass to install lite weight lexon. This problem is not uncommon. Hope you can locate a rear window.

AX993

Scott,
Where did you search ? When I try to search the 993 forum, all I get is a blank page. Can you paste a link?
Thanks,
Glenn

AX993

John, I've got a pretty helpful parts manager at the Porsche dealer in town, maybe he can find one, but I won't be able to ask until Monday. All in all, a bad end to what was a fun Saturday roadtrip with the 993.
Glenn

CAHRERA

Exploding Window Part 1


Exploding Window Part 2


Exploding Window Part 3


Glenn here you go I went by the posted dates.

AX993

Scott,
THANKS !!! I'm looking at the links now.
Wonder why I can't get search to work for me? Calling John D !
Glenn

jlb_94611

Mine hasn't exploded but sometimes after spirited driving over rough pavement I get a crack-crack-crack just like somebody is shotting me with a bb gun. First time I heard it I was slightly downhill from a school and was sure I was taking fire from some kids. Kind of un-nerving when it happens. Maybe 3-4 times in over 2 yrs of ownership... and so far just noise and nothing else.

Land Jet

Funny you guys should talk about a BB attack. Some years ago while driving on a downtown San Francisco freeway in my truck, I heard a loud crack which startled me. I thought it was a rock hitting me. When I got home, I looked over the truck and found nothing. A few days later when removing things from the pickup bed, I noticed water dripping from the ceiling of the fiberglass shell. A small round hole was there and on the floor I found a 22 bullet. Glad it wasn't my head!

The Brewmeister

My opinion is based on only general knowledge of the behaviour of tempered
glass. Others on this board have more knowledge as to the particular stresses
these windows have on them. What caused it is really moot at this point.
The result is that it needs to be replaced. Hope it is an easy fix & keep us
posted.

GabiOsz

Mine exploded in the frame for no reason when I was driving about a year ago, it made me nearly s*** my pants it was so loud.

It happened when I switched the rear window demister on, so I'm inclined to think it was something to do with thermal shock or something else related to the electrics in that area.