Bruce In Philly

I was changing the cabin air filter and I saw a nice pond in the left side of my battery compartment. The drain was clogged with organic guk.

Question: Do these drain holes drain anywhere specific? In other words, is there a hose attached somewhere under there?

There are four, two per side, drain holes with slotted grommets in the battery compartment. None of them appear to have a hose under them. After I unclogged the evil one... left side, toward rear, I ran water into each hole. Then looking under the car, I saw water seeping out of everywhere under there. I suspect there is no hose system. I could not find these hoses/drains in the PET parts schematics either.

Just to be safe, I pushed down some weed whacker line in the all of the holes, then I attached a narrow gauge, hard drain tube to the end of my shop vac and rammed that in there and sucked out a few "clunkers" - what it was... I have no idea.

So..... check those drains after a hard rain, or just pour water in there and see if it drains. These are the kinds of things that may result in issues years down the road.

Peace
Bruce in Philly

Macster

In early models I believe the drain basins should feed into a tube/hose that runs down through the body to the underside of the car. I could believe the hose or tube is at just the right length that going down the road would result in a low pressure area at the tube outlet. If there perchance existed a high pressure are there this could blow air up through the hose/tube and cause water to back up in the drain as one was driving.

I've not been up close and personal with the newer models but it is hard to imagine Porsche would just let the water run down and exit the basin bottom and make its way down through the car to the ground.

BTW, I've always treated the basins and the tubes with gentleness as I do not want to crack the basin (styrofoam I think) or cause the tube/hose to leak water at any point along its length.

Bruce In Philly

It will surprise you, but they do just that with the roof drains. The front drains of the sunroof have a tube that goes down the A pillars and then to hole in the top of the wheel well. From the outside of the car, the terminus is near the gas filler. The water then drizzles down all over everything in there and even over an electronic thingy box with a cable plug/socket. This electronics module gets soaked.

I have not been able to determine what this lonely electronics module is or does. It is located behind the wheel liner, just behind the front wheels, near the bottom where the rockers sort of terminate. (Transceiver for TPMS ?????)

How do I know this? I thought these forward drains were clogged so I pulled off the front wheels and then the wheel well liners to see where all the guts were. Sure enough, way up there was a hole where the internal hose from the A pillar terminated. I pushed weed wacker line up there and it popped out the roof drain hole.

Surprise!

Peace
Bruce in Philly

hansr433

That's good info. I have a 07 C4S Cab. Can someone direct me to photos that show where the drains are located? I have searched the forum without luck.

thanks

Bruce In Philly

Just pull the battery cover off, then the two panels on either side of that. To get those side panels off, you need to just lift the two pieces that run down along the side. Don't worry, you won't break anything. Everything is barely snapped in. Then just aim a flashlight down into the cavities left and right of the battery. You will see them as the slotted gromets are bigger than a silver dollar. You can easily stick your fingers in there.

Peace
Bruce in Philly.

hansr433

Thank you!

Are there any drains in the back in the cab?

JB in AR

I know there are drains in the rear on a cab, but I don't know about a coupe. My technician includes checking and cleaning all drains as part of my annual service.