Water leak behind drivers seat
 

2002 986 checked vents that we know about and cleared them but after a heavy shower we checked and there was still water coming in the carpet down the back right at the bottom where it meets the floor carpet was soaked any ideas ?

any leaks in the top?

If you take the seats out to dry the carpet I would suggest getting a waterproof ECU case. Easy to install and worth the $.

https://www.ecudoctors.com/porsche-996-boxster-waterproof-immobilizer-case-enclosure.html

doesn't appear to be any leaks in the top but can't understand where it could be coming in from ?

Have a friend sit inside the car, top up, while you're outside using the "shower" mode on your hose... have the friend scout for leaks. Stuff a towell behind the seat to mitigate the water under the seat. That should nail it down.

Good luck.

The rear drains could be plugged, could be a tear in the rain tray (especially near where the roof pivots/seat belt spools).

excuse my ignorance but is the rain tray easy to get to ?

IIRC It's what the drain sits into. Big plastic piece. Can't miss it. Collects water and funnels it to the drain hole. One each side.

Yes, clean out the drains. You could put a chamois behind the seat until you find the problem to mitigate moisture going under the seat. You can also use Damp-Rid in the car to get rid of moisture, it’s available at hardware and marine stores.

just to say thank you for all your replies however this is still a mystery as the vents seem clear,the rain trays are not ripped but went out to car after overnight rain and the towel put in was soaked and the water was definitely coming down the lower back wall behind drivers seat so frustrating !!!!

Ways I've seen water get into the cabin
1) Clogged drain
2) Hole in top. Either in the canvas but usually the window
3) Hole in rain tray. Usually caused by a broken control arm stabbing it.
4) Rear top flap torn or not connected
5) Water getting past bolt holes in rain tray. This happen to a car I bought for my wife. During heavy rain events water was getting past where the top frame bolts attach to the roll bar. The rain tray is sandwiched between the top frame and roll bar. I moved the frame out of the way and caulked the area before reattaching the frame.

Hi I read your plight regarding water ingress and living in the UK shows up the weaknesses with leaks. Most people look at the drains but there are a couple of other areas that need to be addressed.
If after clearing the drain holes there is still water ingress there are 2 air intake panels one on each side of the car...when the cover is removed you may find that the plastic panel behind has warped and come away from the body shell allowing heavy rain to run down the inside and it goes into the rear floor wells. This took me 2 years to discover but since they have been resealed - no water ingress! There other area is the front foot wells. I discovered that there is a spongy grommet underneath the battery tray which 'seals' the 2 heater pipes. Over time this wears and allows rain water to run down these pipes into the foot wells. I suffered 2 winters with swimming pool conditions dues to the flow of rain water. I replaced the grommet (costs only a few £s) and since then the car has remained completely dry.

That's great advice... and may save some poor soul fromn chasing gremlins for years.

Thanks!

Also, check to make sure that there aren't any cracks around the drain holes. I found water leaking to my passenger side even though I put guards to keep the drains from clogging and found that there was a huge crack in the foam. I taped it up w/ duct tape for now and it's been holding up.

Same problem here. Drains are Clear, door drains are A-OK. I still have Lake Michigan behind the driver's seat and Lake Erie behind the Passenger seat. Looking for tears in the rain tray & scoops next. BTW I have a rain proof top cover on the so that rules out the roof & window.

Update: I got into the Rain Tray. All sorts of cuts, holes, etc. Filled them w/ Black RTV, then Sealed w/ Flex Tape. Driver's Side was the worst. We had torrential down pours yesterday & last night. That Side's Dry. Passenger Side I have another worm hole to locate.

If you have a rain proof top cover then how is any water getting in the car?