Porsche Boxster Porsche's smallest and least expensive sports car model,the Boxster is a convertible sports car released in late 1996.

The "Water on the Floor Problem"

Old 05-30-2008, 08:52 AM
Thread Starter
Join Date: Feb 2007
Posts: 2
Default The "Water on the Floor Problem"

I found an old post from VOLTAGE that talks about the "Water on the Floor Problem." I have pasted his comments below. This just happened to my 2007 Boxster. Wish I had known about it before.

We had a heavy rain in Florida and all of a sudden my car started acting strange. The horn was blowing on its own. The top was trying to go up and down on it own. The windows went down on their own (in the rain) and would not go back up. I thought that maybe I had driven through a deep puddle and shorted something out.

I took it to the dealer and he pointed out that my floor under the seat was totally soaked. Water had flooded the cabin from behind the seat and had damaged all of the electrical equipment under the seat (I don't know what exactly was damaged, but I know that they replaced two things under warranty, fortunately).

My questions are:

1. Has this happened to others?
2. Is this a design flaw that Porsche is not doing enough to warn about?
3. Does anyone know the equipment that is under the seat and what it would cost to replace?
4. Does anyone know if I have to keep an eye out for other possible future damage that could come up as a result of the water/oxidation?


Here is the old post from VOLTAGE:

Hey Deaner,

If you do not check and periodically clean out debris like leaves from the little drain holes insde the top (accessable
when the top is half open) if the car is left out in the rain(even with the conv top up) water will not drain to the ground and can leak onto the floor andcan short out the alarm and locking PC board which is mounted under the drivers seat.
If you address this situaltion soon you may never experience a problem or if the car has never seen any rain. But - remember even if you wash the car with the top up if these drain holes are clogged water can still find its way to the floorboards.

Good Luck

Old 05-30-2008, 11:12 AM
Join Date: Mar 2007
Posts: 66
Default RE: The "Water on the Floor Problem"

here is some reading

986 Series (Boxster, Boxster S) _ Water behind seat - Drain hole clog fix


Boxster_bath[/align]http://www.dietersmotorsports....[/align][/align][/align]The car would not start, the top and door locks would not operate, and the lights were flashing like a bad 70’s disco video. Being suspicious of water damage on this very wet day , we starting poking around and found a non-factory installed option for this Boxster; an indoor swimming pool.

Under the driver’s seat was about 2 inches of standing water. Normally this would be a small task for a good wet/dry vacuum. However on this model vehicle, a very important control unit was taking a bath in the depths of this new pool.

This little black box controls everything that is even remotely related to the alarm. This includes the top, the door locks, the windows, the lights, and of course the starting of the vehicle.

After removal and disassembly of the control unit, it was apparent that this was not a single incident damage issue. The printed circuit board showed extensive water damage that had occurred over a long period of time. Each time the car was washed a small amount of water would make its way to the pool area, and take a small bite out of this control unit. When the car was left in the torrential downpour, the control unit was drowned for the last time with no recovery.

A car should be able to withstand a little rain, shouldn’t it? Yes it should, and it would if all was well. But this Boxster had one tiny little problem, a tiny plastic problem. The problem was in the water drains for the convertible top. As water runs down the back of the top fabric, it drains into the top storage area. On the bottom of this area there are two drain holes, one on each side. In each drain hole is a little plastic umbrella.

[/align]This umbrella is intended to keep dirt and debris from entering the drain hole and causing a blockage. When water is present, the umbrella floats, which uncovers the drain to allow water to exit the top storage area. In this case, the stem of the umbrella became brittle from the engine heat and broke of in the drain tube. With the left drain tube blocked, the water level increased until it had no place to go but behind the seat. This is why you should check the carpet behind your seat after washing your car or leaving it in the rain. If it is wet, be sure to check the drain holes and their operation.

When the drain holes become clogged, the excess water will saturate this back carpet piece until a pool of water collects under the seat (and over the control unit).

Checking the drain tubes is easy; just activate the top until the metal cover is fully open with the top in the up position. Look in the top storage area to see if both drain covers are in place. Testing the drains is as easy as pouring some water over the drain holes, it should quickly drain onto the ground in front of the rear tires. If this is not the case, remove the drain covers and blow some compressed air through the drains. Anything caught in the drain should shoot out the bottom of the car. Do not replace the drain tube covers with new pieces if they are not there. Later cars do not have these covers. I can only assume that Porsche decided the covers were more trouble than they were worth.[/align][/align][/align][/align]
Old 03-04-2009, 08:53 AM
Join Date: Mar 2009
Posts: 2
Default RE: The "Water on the Floor Problem"

I have a 2001 Boxster S, are the drain plugs accessible in the same way?
Old 03-04-2009, 01:43 PM
Super Moderator
Join Date: Apr 2005
Location: Overland Park, KS
Posts: 3,532
Default RE: The "Water on the Floor Problem"

yup, sure are.
Old 08-28-2009, 09:44 AM
Junior Member
Join Date: Aug 2009
Posts: 1
Default Boxster flooding problems

Similar to the other posts, my '07 Boxster has flooded twice during heavy rain storms. The first time Porsche covered it under warranty. The second time, they said it was not their fault! It seems to me that Porsche should pay for the $3,500 repair due to a defective drain system. I think you should be able to leave your car in the rain, i.e. Shopping, without it costing you several thousand dollars! Has anyone else experienced the same problem? Any feedback would be appreciated!! My email is: [email protected]

Thanks all!

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