MK4 Jetta with sunroof - water coming down the front passenger door wire harness

Hi:

I was inspecting/cleaning my sunroof drains as part of routine maintenance. All four drains are draining nicely, but I noticed an issue and need some help.

To test the front drains, I had my car parked on my driveway with the front facing downwards. I poured water down the passenger side drain hole. At first the water drained slow, so I inserted a tooth pick in the drain nipple to clear out any dirt. There was a bit of dirt that came out. After that, the water flow was OK. But on a couple of occasions, I noticed a very narrow line of water under the dash from the side wall. As well, I could hear some water flowing inside the wire harness. I took off the passenger door wire harness rubber grommet and it was clean. With the grommet off, when I poured some more water in the drain, I could see the water coming out of the white plastic piece on which the rubber grommet is mounted. I could also see water coming out of the bottom of the car, after I had poured water 3-4 times in the drain. This drain is right under the passenger seat area. It seems this is another drain hole? I checked the carpet in that area and it's completely dry.

Some searches on the forum suggest to clean the rubber grommet and put it back properly on the white plastic piece. I did that and ensured that there are no gaps that will allow water in from the drain nipple above it. But still have water coming in the harness grommet.

So far I have not experienced any water leakage in the front passenger area after heavy rains.

Any ideas on what should I be looking for to trace the source of water in the harness grommet? Why is water also coming out of the drain hole at the bottom of the car?

Thanks.

I would check the cabin filter, it is a source of leaks on the passenger side. No advise on the drains, never had them leak.

I had a similar issue and the problem was the cabin filter cover. Mine had some cracks in it after my own botched cabin filter replacement. It's a lame design, but apparently that flimsy piece of plastic plays an important role in keeping water out of the cabin.

Thanks guys, I took the cabin filter out and looked in the bottom tray after I had poured water down the passenger side drain. It's completely dry.

In an attempt to further clean out the drain line, I tried to use the Bentley suggested method, to fish a rigid line down the drain hole. Several forum users suggest using a weed trimmer line. I pushed that through the drain hole and at one point it stopped going any further down, and it didn't come out of the nipple side. I didn't want to force it so I pulled it back out, and put water in the sunroof drain hole. Now there's nothing coming out of the drain nipple, and still water coming out of the white plastic wire harness housing and little line of water down the passenger side wall near the foot well. All the water is now draining out of the hole at the underside of the car right under the passenger seat.

Could the weed trimmer line have dislodged the tubing in the drain nipple or did it block the line further? I read on another site that there's a VW recall for it. Has anyone tried to get the recall done at a dealership?

Please advise.

Thanks.

Get a thicker weed drimmer line and spin it when you are pushing it down the drain.

Update - I took the rubber drain grommet out and sure enough the blue drain tube was disconnected.

I followed these two youtube videos to re-attach the tube:

https://www.youtube.com/watch?v=CIaZ_3qMhvM
https://www.youtube.com/watch?v=4xG2eJzlL-0

Basically push the weed line down the drain tube, pull it out the open end, then thread it through the drain grommet and use it a guide to push it back in over the blue tube.

Tip: While I had the drain grommet out, I snipped about 1mm of the tip to allow water to drain faster.

I had the tube re-attached in no time, took two tries to get it right. The first try detached the tube again when I was pulling out the weed trimmer line as it had edges sticking out at the end. So I cut it a bit and then rounded that end so it would slide out without sticking.

Now the water drains even faster, there's no water coming through the wire harness or down the passenger sidewall.

Learn something new today!

Thanks.