Water in spare tire well - Sunroof drains?

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
My spare tire well in the trunk collects water after a rain. I'm told it's clogged sunroof drains. I tried to do as much searching here on the forum as I could, but I haven't found a description of how to clean / unclog the rear drains

I don't know how to post pictures here, but I pulled back the trunk liners and found water on both sides just behind the wheel wells. It looks to be concentrated there, and then the water flows down into the spare tire well

I'm trying to understand how clogged sunroof drains results in water finding its way into the spare tire well. Can someone please explain the path it is taking to get there?

I think I understand that the rear drains should be unclogged in reverse (from drain to sunroof). Where are the other end of rear drains?

Please don't tell me I need to pull down the headliner to patch up a disconnected line...

Thank you
 

AverageAndy

Well-known member
Joined
Sep 14, 2020
Location
Phoenix, AZ
TDI
2013 Passat
In some passat models, the rubber drain tubes connect to (insert in) an exit tube in the wheel well. It can become disconnected at that point, in which case water stays in trunk.

To clean the drain tubes, I carefully threaded an appropriately sized and smooth edged length of plastic weed whacker line, then followed with a syringe of water to check draining.
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
I really appreciate all the responses. Is it best to attempt to unclog these drains from the drain end to the sunroof? Or can the rear drains be accessed from the sunroof?
 

Tom in PT

Veteran Member
Joined
Jun 7, 2017
Location
Twilight Zone, WA State
TDI
2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
I would try from the drain end. The drain on passenger side is behind the left rear wheel well liner, IIRC. The debris often clogs at the drain end and if you fish a weedwhacker line down from the sunroof you might get binding of the line before it goes all the way to the drain. You will know when both drain lines are free of clogs by parking uphill, pouring a cup of water in the open sunroof drain area and 10 seconds later you see water trickling down to the ground on both sides of the car around the rear wheel wells.
 
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MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
Well. I verified that all 4 sunroof drains are clear. They were not clogged

I then pulled down the carpet in the trunk, crawled in the trunk with a flashlight, and had my wife spray down the entire car. She spent extra time on the sunroof and trunk area. She sprayed it for about 10 minutes.

I saw nothing leaking anywhere in the trunk. I got out, and sprayed the taillights and all around the trunk bulb gasket. Nothing is leaking when testing via the water hose method.

I tried spraying up into the wheel wells. Nothing.

Where is the water coming in? I'm at a loss
 
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Tom in PT

Veteran Member
Joined
Jun 7, 2017
Location
Twilight Zone, WA State
TDI
2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
If you do some google searching you might find other sources of water intrusion- such as a gap in body panels on underside of car, or a bad gasket/seal around the trunk. Poke around this board or do some searching. It must be getting in there some other way if not from the sunroof drains.
 

rocky raccoon

Veteran Member
Joined
Jun 11, 2020
Location
Greater metropolitan Beaverdam
TDI
2014 Jetta Sportwagen
On my 2014 Jetta Sportwagen, my similar problem was caused by one of the rear drain tubes coming adrift from the lower plastic "spout" from which it drains to the street. It required pulling the floor panels and left side inner trunk well panel to find it. None of that was as hard as it sounds. It will be obvious once you gain access. I glued the rubber drain tubing to the spout so it does not happen again.

Note that a water leak in the upper areas of the drain tube or attachments would probably result in wet carpets but water in the spare well is probably from this source.

I will try to attach a photo here but I can't promise. Here goes:

Here goes nothin'. I'm just not smart enough to attach a photo but I'm sure you get the idea.
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
After pulling the trunk liner, you can clearly see that the sunroof drain lines route through rubber grommets in the respective wheel wells. I was able to pull those lines out in the trunk and verify they were cleared. When I was in the trunk doing the water leak check, I never saw any water coming from the drain lines, or anywhere else up above. Thank you for the tip though

That said, I think I found the leak. Pretty sure it's the taillight seal, or the body to bumper seal

I made a video since I can't post pictures

How should I reseal the taillights? And should I pull the bumper down and replace / reseal the body vents?
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
Well, I put new vent relief doors in, and resealed them from the inside. Initial testing showed no more leaks. Great!

Well water is in the trunk again. I found a few body seams that looked too be leaking and sealed those up too. It still leaks

It seems like I have found a fair amount of people reporting this leak issue in the forums and elsewhere. Nobody has gotten any resolution that I can find. I guess I'll join them.

The water leak fogs up the windows, makes the car stink, and generally drives me nuts

I plan to offload the car. Thanks anyway for the help
 

jw4free

Veteran Member
Joined
Aug 28, 2014
Location
NW Boston Metro
TDI
2012 Passat TDI SE
Fortunately for me I was able to drill weep holes in the front footwell bulk area. My conclusion was leaky body seams. I taped clear plastic over the top openings in that section of floor. It has kept the water on the outside with no fogging or wet carpet.

Sorry for your pending loss. But water on the inside of the vehicle is a no go.
 

06bluebeetletdi

Veteran Member
Joined
Sep 30, 2012
Location
Middlesex, NC
TDI
'14 Passat TDI SEL and '13 Beetle TDI
Set up a sprinkler over the car so it acts like rain and let it RAIN, 30 minutes or more. I saw my dealership’s set up for water testing and it was a spray nozzle raining on the car from about 10 feet up. You can also call dealerships / car repair shops see if they have someone that specializes in water leak repairs. Another place to check is the seam around the rear windshield.
 

FordFamilyMan

New member
Joined
Feb 26, 2021
Location
Lawrence, Kansas
TDI
2015 Golf Sportwagen
My 2015 GSW sits uncovered in my driveway which has a slight downward slope from the front to the rear of the car (i.e. the back is lower). Last summer we had torrential rain for a few days and about a week later I opened up the spare wheel well to extract something and the spare and half the BOSE woofer which is mounted on top of the spare wheel, were under water. Probably 2-3 gallons. The headliner was perfectly dry inside, no windows nor the sunroof left open. Long story short, the VW dealer told me that there was an engineering defect. I didn't quite catch the details but it was something like that there were spot welds in the roof around the box frame of the sunroof, that prevented the sunroof frame from being tightly fastened against the outside (frame?) of the car roof. That let water that would have normally gone down the drains, leak into the body, in space between the inner and outer metal. That water found its way into the spare wheel well. The remedy was to take the sunroof apart, fix (grind down?) the spot welds and reinsert the sunroof frame to be tight so as not to let draining water leak through. I think that is about right. They had the car several days, big body job and a new headliner due to the fingerprints and handling of it. I think the dealer covered some (a lot?) of the cost, I ended up paying about $600, the car was off warranty by 2-3 months.
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
My 2015 GSW sits uncovered in my driveway which has a slight downward slope from the front to the rear of the car (i.e. the back is lower). Last summer we had torrential rain for a few days and about a week later I opened up the spare wheel well to extract something and the spare and half the BOSE woofer which is mounted on top of the spare wheel, were under water. Probably 2-3 gallons. The headliner was perfectly dry inside, no windows nor the sunroof left open. Long story short, the VW dealer told me that there was an engineering defect. I didn't quite catch the details but it was something like that there were spot welds in the roof around the box frame of the sunroof, that prevented the sunroof frame from being tightly fastened against the outside (frame?) of the car roof. That let water that would have normally gone down the drains, leak into the body, in space between the inner and outer metal. That water found its way into the spare wheel well. The remedy was to take the sunroof apart, fix (grind down?) the spot welds and reinsert the sunroof frame to be tight so as not to let draining water leak through. I think that is about right. They had the car several days, big body job and a new headliner due to the fingerprints and handling of it. I think the dealer covered some (a lot?) of the cost, I ended up paying about $600, the car was off warranty by 2-3 months.
Wow. Being a 2015, I wonder if there's enough differences in the sunroof mount that the engineering defect started with the 2015 models, and didn't affect the previous 2012-2014 generation? I surely hope so

Interestingly, I've laid in the trunk of the car, tested the sunroof and all other suspected leak points, and I can't replicate the leak on my own.

The dealer I bought the car from agreed to pay to replace the rear window. If that doesn't fix it, then I'll let the car go. Too bad, because I really like the car otherwise
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
Update

I had the back glass replaced today. The shop told me they didn't see any obvious signs of a leak during the swap.

Then, they took it upon themselves to spray water onto the sunroof for about 20 minutes with "a lot of pressure" and lo and behold, water started staining the headliner near the passenger side C pillar. The headliner has developed a bubble at this location, its wet, and in one spot it's now discolored with a yellow tint 😔 I would not have done this type of test myself as I only ever tried to simulate rain, but I suppose I'm happy the leak was found

So I'm back to where I started with the leaking sunroof drains. Looks like it's leaking past the drain line joints I've been reading about. Does the entire headliner need to be dropped to access these joints and reseal them? Or is there another way to gain access? I've searched high and low on the forums, and I haven't found a thread specifically about how to drop the headliner on the NMS Passat; only comments about how it's a PITA
 

Unidiversb

New member
Joined
Dec 23, 2021
Location
Santa Barbara
TDI
2015 TDI Diesel
Same problem here with my 2015 Diesel wagon TDI. During the last rain spare tire well was nearly full so I pulled the 2 plastic caps front . Under the well to allow it to drain and have been trying to air dry it our for days. I cleaned the tail light seals and the hatch drain but since I have everything out during this rain I was able to see water coming down over the drivers side styrofoam jack (tool box) chamber. Made a video and took a picture. I am guessing that its from the rear sunroof drain that is clogged or kinked by the styrofoam that I have seen mentioned. Does anybody know if its warrantied as a defect?
My spare tire well in the trunk collects water after a rain. I'm told it's clogged sunroof drains. I tried to do as much searching here on the forum as I could, but I haven't found a description of how to clean / unclog the rear drains

I don't know how to post pictures here, but I pulled back the trunk liners and found water on both sides just behind the wheel wells. It looks to be concentrated there, and then the water flows down into the spare tire well

I'm trying to understand how clogged sunroof drains results in water finding its way into the spare tire well. Can someone please explain the path it is taking to get there?

I think I understand that the rear drains should be unclogged in reverse (from drain to sunroof). Where are the other end of rear drains?

Please don't tell me I need to pull down the headliner to patch up a disconnected line...

Thank you
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
Update: the windshield shop ended up paying for a headliner replacement. While the headliner shop had the headliner out (they had to remove the front glass and the seats), they resealed the sunroof drain line joints. The leak has since stopped
 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
Another update:

Water is collecting again in the spare tire well. I have heard that the fuel fill door seal can leak rain water into the trunk. If so, are there any writeups on how to replace this seal? It's the one possible ingress point I haven't replaced or repaired

My Passat currently has a leaking oil filter housing, a clogged heater core, and now the trunk leak has returned. If the car market wasn't so crazy right now, this car would be out of my life.
 

Braikabras

Well-known member
Joined
Jun 17, 2005
Location
Drummondville
TDI
2002 Black Jetta
Bought my 2nd 2014 Passat relatively cheap after VW bought back my previous one because of an unreslolvable Adblue issue. This time I just deleted it, no more adblue issue.

I have changed the leaking oil filter housing and clogged heatercore. Just replaced the turbo. Couple weeks ago, someone stole all my diesel from my tank. That's when I found out the fuel door actuator wasn't locking anymore. While changing that part, I found water in the trunk.

Last night, after drying everything in the garage, I spent the night trying to find the source of water intrusion. I started from the bottom up.
Found a major leak on the rear bumper passenger side. The vent grille allows water to come inside when spraying the area between the bumper and quarter panel. Will need to remove the bumper to check what is at fault here, but water is coming inside from the highest of the 2 rubber flaps.
This does not seem to be a problem on the driver's side vent, but I will apply a correction on both sides.

Sunroof drains are clear, water goes where it should (on the ground).

Did not find any leak coming from the backglass. At first, I did not find a leak around the trunk lid. It was rainy so I went for a drive, any new water would be easy to find.

After road test, there was water on both sides of the spare well, and in the well as well. I sprayed the bottom of the trunk lid (in closed position) and looked inside the trunk from the folded backseats. There was a little bit of water accumulating on the lid seal, and after long minutes, drips started to run down the inside of the trunk.
Given the time it took for drips to finally get inside, and the relatively high amount of water accumulated during the test drive, I think there must be some kind of back pressure (or lack thereof) that sucks water inside. That

I have tried to adjust the lid striker to increase the pressure between the seal and the lid, but that was not really possible. Are there any other adjustments on the trunk lid?

There was also another place where water was found, which I was not able to replicate. On the driver's side (see picture), the red area was wet but was not able to see how or when the water appeared there. The yellow area is dirty, as if water is coming in from the wheel well.

Also. I usually park on an incline, nose up. Tried to jack the front of the car in the garage but that didn't change anything.

 

MarshMarlowe

Active member
Joined
Jan 20, 2021
Location
South Carolina
TDI
2014 Passat TDI SE
I also had water coming in at the boot vent grilles. I replaced those, and applied some sealant around the edges. That fixed that leak. I don't believe the bumper cover was ever really intended to be water tight

The water you're seeing that you have circled is likely running down the C pillars, and originating at the rear sunroof drain tube joints. The headliner was dropped in my car, the joints resealed, and that leak stopped. For a while. Then it came Back

With all the other issues I had with this car, I just went ahead and sold it.
 
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