Bjbpe

My 928S4 has the newer style taillights; nothing special, just the style that came out in 1987-1995.

When I run the car through the car wash (at 79 years of age, I am not quite as fastidious about hand washing as I used to be) it would appear that water somehow touches the stop bulb on the passenger side. This, of course, results in the bulb breaking due to cold water on hot bulb.

It must be a small amount of water as I never find water in the bulb compartment. There is a vent for the compartment and I tried attaching a soda straw to the vent to move any leaking water away from the compartment and I thought for a while that was working but now it seems no longer to be effective.

A couple of years ago someone backed into my car while it was in a hotel parking lot overnight. Of course I never heard from the culprit but one of our good members volunteered a replacement (name withheld so he won't be asked for other goodies but I greatly appreciated his help). The unit seems to be weathertight but the above problem is still with me.

Does anyone out there have any experience regarding a similar problem? Any fixes?

SteveG

You say it leaks but you never find water in it. Seems you need to do some sleuthing. Try to recreate the conditions at home with a garden hose.
Does normal rain have the same result?

You need to find the source of the moisture. A seal may need some help or replacement. There are no rules in areas that are not visible. Alex caulk, silicon gasket maker can be use to place a bead that directs water away from where it is intruding or build up a ridge that the seal fronts against.

Mark Anderson

I would add the drain holes to the inside back of the bumper cover. Porsche later recomended that

MjRocket

Mark how large of holes do you recommend?

Thx

MainePorsche

MJ,
I made mine a little larger than these.

MjRocket

Thanks brother...I need to do this.

jej3

The issue is probably the same on my 1990. Sorry, no pics. But the heat of the bulb and the numerous water cycles caused the passenger taillight to have a crack on the housing directly above where the bulb was which kept blowing.

To remedy,

- I used an epoxy to goop up the crack and seal it.
- Replaced the harness with a used harness as my bulb receptacles were irrevocably corroded beyond repair.
- Drilled NUMEROUS holes in the bumper cover underneath and towards the back of the bumper cover cavity where the light is held.

To investigate, take out the light fixture and remove all bulbs. Run water over flat horizontal upper surfaces. You will find your leak; I am sure of it.

Post here if you need more help.

jej3

Don't take this the wrong way....

Machine washes and 928s don't mix very well. I would find someone to hand-wash as there are all sorts of bad things which can get wet from the hi-pressure machine washes.

MainePorsche

An absolute +1 on this.

Bjbpe

Thanks to all for their comments. I'm going to put in the drain holes as recommended.

Alan

I'd also add a seal so you don't get water streaks running all over the rear bumper cover everytime you have washed the car.

Alan

Randy V

Did you install those drain holes, Alan?

Alan

Well - I suppose its more like I 'uninstalled' them - but yes - stock there is only the big drain at the back (doesn't drain the whole space very well).

Alan

andy-gts

that foam gasket is a great idea…..that streaking always bugged me as it drained down the bumper!!!

Randy V

Whenever I take mine through the hand car wash I direct them to spend a bit of time with the air hose blowing out the water that accumulates under the lights and reflector strip.