pancholi

looking to clean out the water drainage pipes this weekend.
are there 2 pipes in front wheel well and 2 pipes in the back wheel well?
is there a separate drainage pipe for the air con/ front ventilation?
presuming that there are drainage pipes on the back( i have seen threads and youtube for the front pipe/pipes)is it a matter of removing the rear wheel and arch cover?
any advice welcome...
many thanks

JAGMAN1

In back there are two small tubes that can be seen without removing anything.

In front the two primary cowl drains are the critical ones. Remove the three rear most screws that hold the wheel well liner in place. With the three screws removed you can bend the plastic enough to get at the drains. Shine a flashlight and you'll see a star shaped tuber grommet. Pull the grommet out and clean out any debris. Repeat for the other side.

pancholi

thanks for the info.
rear ones cleaned.
the front ones..
are they about wrist hight up the well or elbow height?
as i have the arch extenders fitted to the car the plastic arch liner is a devil to flex.
if its to high up may need to remove the wheel and the whole liner .
cheers

JAGMAN1

They're more elbow height or even deeper. I just did mine for the first time ever a few weeks ago and couldn't believe how much debris came out. I will do it annually from now on. I was not having issues before hand, but noticed dripping from near the front wheels the day after I washed it. I figured there must be a backup for water to still be dripping 24 hours later. I was right.

Pulling the rubber grommet out really helps to get at the debris. The grommet reinstalls quite easily too.

Could you post a few pictures of your wheel arch extensions. I'm debating adding those. Thanks.

JAGMAN1

One more thing, I turned the steering wheel full left to do the right side wheel well and full right to do the left wheel well. That afforded me plenty of access with the wheel on.

jmorgan911

I took the cayenne to a local indy shop to clean the drainage pipes, and AC pipes. He said there were only two drains for the sunroof (in both front corners) and 2 drainage pipes draining the front cowling. He didn't locate the rear ones.

Unfortunately I still have that sloshing sound when driving. Any idea if there are drains for the rocker panels specifically?

JAGMAN1

Hmmm. Rocker panels are covered with some plastic covers. I might remove them and give the area a look over. Remove the rubber grommets and check for blockages.

As for the rear drains, there are two just above where the exhaust tips turn 90 degrees towards the center of the car. One on each side.

The other area two areas to look for are:
1) rear hatch area. You'll see two black plastic covers around the hinges. The water drains underneath them. Pull those off and poke a zip tie through the holes to ensure they're clear every once in a while. The cover is the the piece that's fastened to the car's body and not to the hinge itself.

2) the AC evaporator drain is another common culprit. You can see that in the passenger side footwell just above the panel that covers the pollen filter access.

As I mentioned earlier, the cowl drains up front are the place that I had about 2 pounds of leaves blocking the drains. Each discharged about a gallon of water too. But if your mechanic just checked those then...

pancholi

i cannot believe the ill thought out design of the cowl drain. i removed the grommets and several litres of water came out. there was a lot of silt that had blocked the grommets. i have not fitted them back on.
every cayenne should have this cleaned periodically.

are the rocker covers the 'silver' plastic cover in the engine bay? does water trap there?

also the AC evaporator drain, is that with in the cabin( just to clarify as you have mentioned passenger side foot well( but will have to see which side the pollen filter is on my UK spec car))

thanks

JAGMAN1

I have to think that the cowl drain grommets were put there to keep mice and other animals out. Side effect is that they keep sand and leaves and water in. I too thought about removing them altogether... The rocker panel covers are the black plastic trim panel covers the run on the underside of the car between the front and rear wheels. They run along each side of the car. They won't really hold too much water, but removing them will reveal a few grommets that plug the body of the car.

The a/c drain is a rubber tube beneath the cabin filter. Right front on a U.S. Car.

seafeye

I am replacing my headliner because of this. I think it is a poor design. There are 4 almost identical drains. One at each corner.
First off the VW and Porsche are the same system. THere is a reservoir at the back of the sunroof frame that can hold a little water. If you park on an incline the water can and will go overtop of the drain and onto your headliner. I had two wet spots at the back of the sunroof on the main headliner.
Couple good things about removing it. I am going to a full Alcantara black. Got all the handles lights switches from a turbo. All but the main headliner. So having a local upholstery guy install it. With some custom touches. Should be done in a week or two.

While it's out i was able to see why it leaks and where. Best advice is avoid parking in the rain. Especially on an incline.

jmorgan911

Thanks to all the great info hear I was able to rid the car of all excess water! BTW I have a 2011 958 CTT.

The front cowl drains are located behind the front wheel arches. They contained some dirt and leaves but seemed open.

The rocker panel drains are located behind plastic shields that have to be removed on both sides, below the sides of the car. Doing so exposed 3 rubber plugs, which drained almost 2 gallons from one side and a little water from the other side. Water was clear, no rust. I left them unplugged, since they are already hidden behind plastic shields.

We forced compressed air into the AC drain and sunroof drains, all was clear although one side had a little more resistance (the side with water in the rocker panel). Still not sure if this is how the water got into the rocker panels, but the sloshing sound is gone at last lol

John

shenofjo

not sure if this is addressing the 958 cayenne or not, but just wanted to mention I worked on my dad's 958 today and was able to remove the front rubber drain plugs without any tools. Just move the front wheels to the full left or right, see the opening of the wheel well cover behind the wheel and reach towards the rear. you will feel the rubber plug. pull it out and done! I ended up having a blockage on the driver side and this helped quite a bit with clearing the water flow.

I'd like to know if there is a way to test the rear drains.