very useful thread - thanks!

 

OK - I said I'd give an update in a few years. Is ten years long enough?

This is with the front trim removed. I'll take some better photos in the daylight tomorrow, as the flash makes it difficult to get good detail. But there's no rust, and still the same screens, i.e. the sealant didn't cause the screens to crack, and there's no squeaking either.

 

Timely thread. My car should be done at the body shop in two days. Was in for cowl rust fix but I went ahead and resprayed bumper and hood at the same time. I hope others have not experienced this issue - was pricey and invasive to fix.

 

The other three corners - I've lifted the plastic-trim out of the grooves in the windscreen surround, so you are able clearly to see the danger areas

Ten years on - no sign of rust.

As a side point, note the slight shadow (depending on camera angle) that the screen trims can leave. The paint is certainly slightly 'rubbed' by the trim.



Front LHS

Rear LHS

Rear RHS

 

One test is better than a thousand theories. Good follow up.

 

Great write up and follow up.

Just a note, it’s not just rain but washing the car with water that will result in the same corrosion issues. Many 993’s were babied right from the factory with very little exposure to weather but they were still washed and it’s extremely difficult to get the water out of the seals.

 

It's funny that Porsche says to fill it, yet they delivered the cars without it....

On a front windshield, should the filler material go all the way around?

 

Steve- yes, per the TSB

 

I just had my windshield replaced by a very competent individual- perfect work on a low mileage
2S. Not a bit of rust or corrosion- it was formally a West coast car.

We used Porsche moldings and ..... I have noticed that the exterior gasket is easily capable
of not fully bridging from paint to paint on either side of the channel. If I push down on the
gasket, I can make the bridge move to where the original gasket was. The installer suggested
using a heat gun to GENTLY warm the gasket and then tape it down in the "proper" position
during cooling. Not sure if I would bet on that being able to prevent the vast majority of water from
sitting at the bottom.

Is this filling of the channel advised for all of these cars? How long does it take to do?

 

Windshield: I take two small toothpick pieces that I put under the bottom corners after I wash the car. Lots of water drains out.
Rear window: I pull the window seal out on the bottom and halfway up the window and soak up the water with a towel. Leave the seal out overnight until it all dries out and reseat.

 

I think if you didn't fill the gap all of the way around, water could easily find its way in from the top and sit under the sealant at the bottom. Either do it all, or none.

The external trim is just cosmetic - I wouldn't bother trying to make it waterproof.

Steven - I can't visualise what problem you are seeing - how about a photograph?

 

All correct above. The ws discussed here was installed off a few mm. Either the installer eyeballed it or didn’t use the spacers called out for in the service bulletin. More likely he didn’t have the templates needed to set the ws into the adhesive and now the ws sits proud of where it should be. Now the trim seal won’t cover the cavity. The trim seal isn’t wide enough.

Heating the seal won’t do anything. The only possible fix is filling the cavity with the foam rope or seam sealer to give the trim seal support. I did front and rear ws both cavities using 3M Window Weld ribbon sealer. Putty type substance that doesn’t cure and is removable.

 

Mike- could you clarify your comment... actually do you have the service bulletin that discuses templates and spacers?

It is my understanding that the WS is not set into the adhesive- if it was, it would not be removable and capable of being
lifted with "toothpicks".

Maybe the original poster, who seems to know the most here, can make a comment?

 

It seems there may be some confusion creeping in

WS = windscreen - this is certainly bonded-in and sits on a bed of sealant - see my very first photograph. You can clearly see this.



This is the WS/plastic surround sitting on factory sealant.

To be clear - a new WS consists of the actual glass sitting in a hard plastic surround, which has a narrow channel into which the cosmetic trim fits.

The trim, a flexible rubber/plastic strip, just fits into this channel in the WS plastic surround - the channel is shown above. The rubber/plastic trim performs no function other than to hide the join/gap between WS/plastic frame, and the actual car's metal aperture.

Here is the particular TSB concerning filling the gap..

 

Without seeing your car, or a photograph, your description suggests two possibilities to me.

1) The screen has not been located correctly in the metal aperture.

2) you have the wrong rubber/plastic trim on the car.