Rain leaking somewhere and settling in the spare tyre well

[luckymacy]

Anyone have any idea where it's common for rain to leak into to the rear of the car from the right rear area other than the rear light cluster area? I've removed the right rear interior plastic panel and took the spare tire out and done some testing. I pulled the right rear light assembly and convinced myself it's not leaking through the seal around the light housing but put some silicone around the seal and put it back together and retested to find it's still leaking but perhaps not as much? It seems like the water is running down from the roof or upper hatch area of the car and settling down into the right rear area behind the light assembly then pools and eventually runs into the spare tire well. I've been pouring water over different parts of the car and waiting to see what happens but no obvious single area seems to point to the root cause yet. I'm looking for ideas! This car has a lot of the problems others have seen. Door windows won't roll up any more and the engine cluster LCD is totally shot. Lots of creeks and groans when operating. It has character! Looks like I'm going to turn the garage into a work shop over the holidays and do some repairs!

 

[tompearson]

Have you checked the sunroof - if you have one - drains. I think the rear drain hoses go down behind the rear light clusters.

Otherwise, does your rear wiper jet work? - I think the hose to it can detach in various places and cause this sort of problem as well.

 

[ianysm]

Radio Aerial can leak but not sure if it would end up in boot?

Also as above, rear wash often leaks and causes rear boot release to go faulty and boot interior light. Worth stripping the boot lining to have a look

 

[Westy]

Have you checked the water pipe to the rear washer?

 

[A3Tom]

Have you checked the water pipe to the rear washer?

+ 1

 

[luckymacy]

Thanks for the quick replies! Yes, before finding this Amazingly Fantastic Forum I verified the rear wiper washer and line worked properly and did not cause the leak.

Where can I find online where the sunroof water is collected and drained and its path towards the back and how it's supposed to terminate to the outside in the back area? I don't see a thing in the car that looks like a sunroof water drain or a water line in the back that isn't already hooked up to something...but I think the post referencing the sun roof may be spot on and I'm going to refocus my 'scientifically applied water tester' to that isolated area and see what happens very shortly and will report back!

 

[tompearson]

MKIV Jetta pics (they seem to like them in the US) and an A6 diagram. I pretty sure this is basically the same as on an S/A3.

 

[luckymacy]

It's somewhere between the top of the hatchback door on the right hand side down to the drain opening on the bumper but NOT including the drain itself. That includes a good test of the antenna base too. Nada leaking through it.

So if it pour water from the top of the roof it leaks into the car the most. If I pour water into the area around the right rear light housing, it leaks a little. It's almost like it's leaking through the pillar and the higher I up the pillar I pour the water from the more it leaks but there's no obvious place it could be leaking into the steel pillar. I temporarily duct taped off the gap between the top of the right rear light housing and the car and it seemed to help some but not elimate the leak. Water seems to be pooling in two places 18 inches apart and one spot about a foot higher than the other. Ughhh. The high spot is from the inside top of the right rear pillar above where the right rear panel fits and behind the top of the right rear tail light area. The water has to somehow rolling down hill from the top of the car somewhere??? The second spot is from a vertical gap in the steel on the inside of the spare tire well on the inside of the where the right rear bumper drain is located (but it's not coming from the drain itself - that's easy to test!).

Even though the hatch door seal seems to be in perfect condition and fit, could it be leaking from underneath? Doesn't seem plausable but then again....I really want this fixed. Don't want to be driving around anymore with the rear well acting like a 4 inch deep swimming pool after a hard rain!

 

[luckymacy]

For the record, I think I got most, if not all, the leaking water. I could not pinpoint the exact point(s) of entry. In the end I took off the right rear tail light housing and gobbed clear silicone over every interface of every part that was exposed. Anywhere 2 pieces of plastic, plastic and bumper or plastic and aluminum met I sealed it. I put extra silicon all around the opening of the tail light cutout on the car body where the seal meets, I put an extra bead on that made a dam above the tail light cutout and some on the tail light gasket itself. After the tail light was installed I put some temporary tape on each side of the car to tail light interface and ran I nice flat bead over that area too then took the tap off so it would be neat and not noticeable. In the end, I never saw another drop of water in the car. Called it a day and put the car back together. Time to move on to the next project with is to get the odometer changed from Km to miles and get the LCD fixed in the dash...

 

[ash_pearce]

i had exactly the same problem, after hours of searching with the mrs holding the hose pipe on the car whilst i was in the boot i gave up.

I tried all of the above things, lights, ariel etc in the end i settled for two small holes drilled into the spare wheel well and one behind the light all painted up so will never rust and problem solved!

 

[Kingston]

I had this on a Golf mk3 looked everywhere boot seal everything. Turned out to be the seal round my rear lights. It rained, water would seep in and make its way into my spare wheel well and some how into my back seat passenger foot well. Was a mint Golf mk3 Full body kit front and rear bumper, m3 side skirts, m3 mirrors, sweet sexy spoiler custom made exhaust etc in Ferrari red. Wolfrace Voodoo wheels 18" with 40mm tyres on. Full suspension set up dropping it 40mm. Got some nice pictures to remember her by. mmm

 

[cabby86]

I have not had any problems with my S3 and leaks, but I did own a 3dr MK4 Golf and leaks were a common problem in the MK4 (I know the A3/S3 and MK4 are similar),

The only thing that no one has mentioned are the rubber cabin air vents behind the rear bumper, these could have perished resulting in water getting in and finding its way into the boot, this is a problem on MK4's and is a relatively cheap and easy fix, I know the A3/S3 has similar vents as I checked mine when I last took the rear bumper off.

Hope the above might be of some help.

Cheers

Chris