Wet Front Passenger Floor - Gasket Failure?

[nroakley]

I've had a repeated water infiltration problem during periods of heavy rain in the last year (especially in cooler weather). The water keeps pooling in the front passenger floorboard of my '01 TDI - NO SUNROOF. I've pulled the carpet up and dried the carpet pad; I left the carpet folded back and ran a test with a water hose to try to find the problem. With the front right dash panel removed, I can see the water draining into the plenum and out the drain into the front right fender well. I've removed the wheel well liner; it is free of debris. When enough water comes into the plenum via the drains in the cowl, water does pool up against the cabin air filter enclosure (but not over the top). The only possible entry point I can find is around the cabin air filter enclosure. I just found a similar problem with Passats.

Has anyone else had this particular problem that couldn't be explained by clogged sunroof drains, clogged cowl/plenum drains? My car has no sunroof, and the drains are completely clean, but I still collect water. When I run the hose on the cowl/wiper area, I can see a small stream of water running down the front firewall. This afternoon, I coated the cabin air filter housing gasket with silicone adhesive sealant in hopes of stopping the leak before rains come again this week. We'll see what happens. Any thoughts?

VWvortex Forums: VW Service Action P9 (water entry)...anyone else?

[Steved]

I too have suffered the driver's side front and back carpet curse. I discovered the problem when I couldn't stop my windshield from fogging up. And, it wasn't the sunroof drains. If you've checked your sunroof drains and they are clear (or you don't have a sunroof) yet your carpet remains squishy, here's the fix.

Remove the windshiled wiper arms (details in the TDI wiper motor service how to section, it's easy). Then remove the black plastic slotted valance that's under the wiper arms (this too is in the how to section). Once this is off you'll have pretty good access to this cavernous void. My car was parked on the streets of Richmond VA for a few years before I bought it and as a reuslt this area was filled with tree crud when I got the car about 2 years ago (it's an 03). I cleaned it out as best I could but I never removed the valance. Once removed, you'll be able to get much more of the debris out. The insidious part of this problem was my drains were not completely clogged, when I sprayed the valance with water it still ran out of the back part of the fender (as well as into the car over the clutch peddle), indicating the drainw as working, but not quickly enough. But, when I removed the fascia over the driver's feet, I could see the water dripping from a gasketed black plate, the other side of which lives in the afroementoioned void, so I knew where the water was coming from.

Using a combination of compressed air with a long nozzle, a garden hose, spray detergent (Spray Nine) and a pick up tool, I was able to remove the blockage from the drain area (you can't actually see the drain inlet in this void area unfortunately, it's aft of the hood hinge and just not visible). The pick up tool was most effective in lifting leaves, pine needles etc out of this well. While I was in there I lubed the wiper mechanism and rust inhibited the strut nuts, the latter are a well design and retain water and rust. I also glueed a long strip of fiberglass window screen material that I cut to size to the inside of the valance louvres and drains before reinstalling it. I also installed the screen under the wiper arms before reinstalling them. I sprayed some rust inhibitor on the hardware over the driver's feet, there was some minor rust.

If your carpets are wet shop vac them of course but also be sure to pull the drain plug under the rear section, I did so and was able to shop vac a quart of water out of this hole. I left a rag in there for a week as a wick, water continued to drip out for several days. If I'm lucky I'll avoid the mildew issue and not have to replace carpets, so far so good.

This is really a poor design on VW's part, to have so many places where leaves can get in but can't get out , it will inevitably lead to this type of leak. The screen retrifit is not perfect, but it will help.