Wet Driver's Side A-Pillar... Help Wanted!

[AudiPilot]

After a search on the forum (via Google, not the integrated site search) I didn't see anything specific to this... Here are the facts:

- I've owned the car a month and it's been kept out of the rain.
- Today I picked up my car from the body shop after they reattached some door molding (unrelated to the windshield).
- They did a quick wash (the only source of water recently) and the driver's A-pillar was freshly saturated afterwards.
- I checked the left sunroof drain (trimmer line went straight through and came out totally clean -- I also can't imagine getting enough water in the sunroof seal from a quick wash like that for the sunroof drain to be a potential source).

Based on the way the water was propagating it seems like it would be coming from behind the windshield along the left vertical edge -- wetness was concentrated on the "middle" of the A-pillar, not confined to the top or bottom. Could it be entering a bad windshield seal after running down the circled channel? Is there anything else behind there that might need addressing once the windshield comes out and before a new one goes in?

https://www.rs6.com/attachment.php?attachmentid=19041&stc=1

The moisture was concentrated along the oval-circled section of the A-pillar.

https://www.rs6.com/attachment.php?attachmentid=19042&stc=1

But then a well-recommended windshield shop says it's very rare for a windshield to just "suddenly start leaking" (though I have no way of knowing how long it has been leaking as a new owner). They say, "we'll replace your windshield and guarantee it doesn't leak, but that doesn't guarantee the car won't leak in general." Of course, that's fair.

Suggestions welcome! The windshield is pretty blasted anyway so I could replace it, I just want to be sure I don't go after the wrong thing for no reason. Thank you for any help!

[hahnmgh63]

1904319043

[AudiPilot]

1904319043

Thanks! I did check the forward sunroof drain, and it seemed clear. Can it be cracked and leaking inside the tube that runs down the A-pillar?

[AudiPilot]

I’m seeing the primary possibilities:
1) Cracked drain assembly (requires headliner removal? :doh:)
2) Cracked roof weld (in the channel, body shop repair with epoxy)

Would be grateful to hear from anyone who’s had and solved the issue!

[DHall1]

Take the molding off and perform a closer inspection

do you hear and wind noises at high speeds

[hahnmgh63]

What DHall1 said, you definitely need the molding off for further inspection. I doubt the drain would crack unless someone poked something into it if they had the trim off earlier. Possibly roof weld but I'd go with drain or windshield first.
Pull the trim off and sit inside while someone sprays the windshield with water, have them start low and slowly work there way up the pillar towards the top and onto the sunroof.

[RS6-2-NJOY]

I would suggest taking the A pillar cover off and while you're inside the car have someone hose that side of the car while you look for water leaks

[AudiPilot]

Take the molding off and perform a closer inspection

do you hear and wind noises at high speeds

Sage advice, and as a matter of fact, yes I do hear wind noise... see, they don't tell newbies what you can pull off (molding) and what you can't... Guess we found the source, thanks for the insight! Thanks, Audi, for steel rivets...

https://www.rs6.com/attachment.php?attachmentid=19044&stc=1

Already have a body shop working up the quote... Then naturally picked up my first CEL on the way home. :doh: Made it just over 1,000 miles since purchase...

[AudiPilot]

Many thanks to all who replied as well! One of the aspects that made prospective ownership tenable was the vast repository of experience contained herein...

[PCMacDr]

So, those Moldings just pull off ?

Easy or what ?

Do you have to put adhesive on it to place it back ?

I am getting some water on passenger side and I have checked, Sunroof, cleaned out drainage area ( under the Coolant Res )

thx for sharing

[AudiPilot]

So, those Moldings just pull off ?

Easy or what ?

Do you have to put adhesive on it to place it back ?

I am getting some water on passenger side and I have checked, Sunroof, cleaned out drainage area ( under the Coolant Res )

thx for sharing

It seemed pretty easy... I don't make a habit of just pulling on things until they just pop off, but the service manager at my trusted body shop was very confident as he pulled it away (carefully) at the top (enough to see underneath). Doesn't have adhesive but rather held in place with friction, and it re-seated fine. We didn't remove it all the way, just enough to verify that it's definitely rusted through underneath and the cause of the leaking. There's 15 years of dirt/dust/debris behind the strip, which I'm sure collected water and allowed it to sit on the rivets.

Seems like if the strip got damaged (or wouldn't stay when reinstalled) there are cheap-ish options to replace: https://www.ebay.com/itm/2000-2001-2002-2003-2004-AUDI-A6-C5-4-2L-LEFT-WINDSHIELD-SIDE-TRIM-SEAL/143402854578

[PCMacDr]

thank you kindly for the detailed explanation

Will tackle this once its stops raining here in Cali ( much needed )

[AudiPilot]

thank you kindly for the detailed explanation

Will tackle this once its stops raining here in Cali ( much needed )

Absolutely! I plan on asking the body shop for some in-process photos, so if they come through with that I'll post showing the repair.

[AudiPilot]

Here we go... the windshield was original, so I’m pretty sure the left and right water deflectors (black trim) had never been removed. This allowed dust/dirt to accumulate, and then any time it got wet the moisture sat on the retainer clips. These clips and rivets are steel, and are treated only lightly with some zinc coating (body shop called it a “designed manufacturing defect”). So you can see the rust migrated to the actual body a bit, but not beyond repair. Driver side was far worse than the passenger, but definitely mitigating both completely.

For those with an RS6 that has never had the black side trim removed under your ownership, could be worth an inspection to verify you don’t have the beginnings of what I ended up with.

https://www.rs6.com/attachment.php?attachmentid=19052&stc=1
https://www.rs6.com/attachment.php?attachmentid=19053&stc=1
https://www.rs6.com/attachment.php?attachmentid=19054&stc=1
https://www.rs6.com/attachment.php?attachmentid=19055&stc=1

[Muggy]

Thanks for the detailed photos...I'm glad my car has been a garage queen for most of it's life. This definitely seems like it could be the cause of the ill's on my C5 A6 2.7t though... :rolleyes:

[hahnmgh63]

Garaging helps but I would say it is the conditions it is driven in. I've seen multiple NE cars and they all show the effects of Salted roads compared to our West coast cars. If you live in the NE, don't drive your cars in the Winter. I bought my '06 Cayenne Turbo S in 2008 from Maryland. With only 2yrs on it there was already the beginning of damage much of the Cadmium plated hardware. When I got it home (flew out to pick it up and drove it back 2k+miles) I pressure washed the whole underneath. Now 10+yrs later it looks better underneath then it did at 2yrs old.