A6 avant - leaking - rear footwell

[JonAvant]

Hi all. 

I’ve had my 2020 avant 45TFSI for 4 days, and when I got in yesterday it smelled really musty and damp. I checked the carpets to find the rear offside footwell soaked! More towards the centre. It’s obviously been leaking a while due to the musty smell. 
is this a common issue? 
 

I’ve now rejected this vehicle but would like to know before I look for another …

[Steve Q]

Not heard of the c8 suffering from this. But can be a number of things from looking at previous A6 models such as blocked water drains allowing water in the cabin, leaking pollen filter housings, leaking sunroofs, leaking door or window seals. 

[NelsonP]

I just bought a 2019 A6 Avant and same issue. The offside rear footwell had about 1/2 an inch of water in it earlier today.

The Audi dealer I bought it from is investigating, have read elsewhere that there is a TSB for it so hoping to get it sorted.

Will post an update here when I have it.

[NelsonP]

I reckon this is the problem....

 

[JonAvant]

2 hours ago, NelsonP said:

I reckon this is the problem....

 

Would the front. Footwells not be wet though? Was only my offside rear which was drenched 

[NelsonP]

As I understand it the water gets in through the air inlet, into the heating system and out through the vents under the seat. I'll see what the dealer says...

[Daniel11]

Yes, it is a common problem. I have it to with my A6 C8. What I try now is to remove falling leaves every week under the hood and near the wipers. It is ridiculous that this has to be done on a car with this purchase price. The car dealer says there is nothing else they can do about it. 

[Daniel11]

Looking at the video, I will try this soon. 
Can you leave the hole open so leaf debris and water can get out more easily? I actually don't see why it couldn't be done. Anyone have an idea?

[NelsonP]

Looking at that video there is definitely something that could be done about it. Just redesign and insert some replacement drains.

In my case, if the dealer can't sort it I will return the car for a refund. It has been in their workshop for 2 weeks now (!)

Audi UK must be aware of this and need to do something about it.

Similar unaddressed issues in the past have resulted in class action lawsuits. The A4 B8 had incorrectly specced piston rings between 2009-2011, which resulted in excessive oil usage. Audi refused to deal with the problem until a US-led class action lawsuit changed their mind.

Let's hope that they are more proactive this time.

Edited November 9, 2023 by NelsonP

[NelsonP]

Similar issues on the A5 perhaps? The comments there suggest Audi are charging customers to resolve it, which is pretty shocking as it is obviously a design fault.

 

[NelsonP]

Same same?

 

[Daniel11]

The latter indeed seems to be the same problem indeed. 

Funny enough, a friend of mine has an Audi A5, same problem. He went to Pon company which is the importer of Audi in the Netherlands
They fixed the problem by installing some kind of tube, and they did it for free because they knew the problem. I have to call my friend this week for more information. Then I will also contact Pon company.

When I showed the problem to the Audi dealer in my city, they reacted as if they saw it for the first time, which must have been a lie. 

I will keep you updated here.

Edited November 12, 2023 by Daniel11

[Mandeep]

Got the same issue with my car. Audi A6 2019. Poor video on my part. But basically having a nightmare with Audi UK who have refused to cover the cost of diagnostics which is £140.00 per hour. The diagnostic work will take hours for Audi to find the problem. Not sure how on earth the water is getting into the car. 
 

Audi UK don’t care about the class action lawsuit either. Link below.  
 

https://www.gcmsettlement.com/#:~:text=In the action%2C Plaintiffs%2C individually,result in water or liquid

Any and all advice welcome. 

[NelsonP]

@mandeep Identical symptoms to my car. I'd only recently purchased mine as an Approved Used Audi and it was rectified by the dealer eventually.

They did not share much detail, but mentioned that the source of the water was in fact from under the wheel arch, and that the problem is rectified by fitting self draining bungs.

You have no hope of removing all of the water with your vac as it sits in all of the cavities under the floor. Over time this will cause a mouldy smell in the car if not rectified.

It is a big job, as all of the water must be removed from the car, and its possible that trim, carpets and any water damaged components will need to be replaced. This is why Audi will not acknowledge it.

Perhaps the community on here, the fact that there is a class action suit and that Audi almost certainly have a TSB about it will persuade them to listen.

Failing that I'd go to a consumer organisation like Which? and see whether they would be prepared to act.

[Daniel11]

Hi Sandeep, 

Audi The Netherlands helped me once with this problen and wanted me to pay the invoice of around €600. I refused to pay andtold them that this is a structural problem and there is nothing I can do about it. After much whining back and forth they agreed anyway. But I was also very angry and being angry in a showroom full of people wanting to buy a new Audi probably helped because they wanted me to be calm:)

I have contacted Audi afterwards and they still don't accept that this is problem is a construction fault. They probably don't want to admit due to the costs it will bring with this type A6. 
I keep pointing this out to them every time I am at Audi for service. 

I had the same problem as you that water was getting into the car. What I do now is I always removed the leaves in the fall. 
I do that around the wipers and under the hood. Also, I open the plastic parts under the hood around the wipers and remove leaves etc here as well. I also use a vacuum cleaner with a long thin hose to get to the parts where my hands can't come and sometimes I also use a a high pressure blower (compressor). If there is still water in there, it has to be sucked out first because that (rain)water will come inside the car once it gets to a certain level. 

I know, it's ridiculous that you have to do this with a car of this price. This is my 4th Audi A6 and I have more problems with it than this alone. So I think it is the last Audi I bought. 
I hope this helped. I did not have any problems anymore after I have been removing the leaves (almost every day in the fall). 

 

Edited January 15, 2024 by Daniel11

[Ender]

How do I replace the drain bungs with self draining ones where do I get them in the uk I don’t mind doing the job myself just need to know where and how to do the job.

[JGarcia1283]

See Service Bulletin TSB #2060335/3 

https://static.nhtsa.gov/odi/tsbs/2020/MC-10185208-0001.pdf

2019 A6...My car is at the dealer will post how much it costs as vehicle is out of manufacturers warranty an I don't believe my All State Powertrain Extended warranty will cover it.  Well see.

[Cal0403]

On 1/15/2024 at 2:41 PM, Mandeep said:

Got the same issue with my car. Audi A6 2019. Poor video on my part. But basically having a nightmare with Audi UK who have refused to cover the cost of diagnostics which is £140.00 per hour. The diagnostic work will take hours for Audi to find the problem. Not sure how on earth the water is getting into the car. 
 

Audi UK don’t care about the class action lawsuit either. Link below.  
 

https://www.gcmsettlement.com/#:~:text=In the action%2C Plaintiffs%2C individually,result in water or liquid

Any and all advice welcome. 

I have just discovered this exact same issue on my 2019 A6 Avant. Did you get it resolved?

[Cal0403]

On 4/15/2024 at 4:15 PM, JGarcia1283 said:

See Service Bulletin TSB #2060335/3 

https://static.nhtsa.gov/odi/tsbs/2020/MC-10185208-0001.pdf

2019 A6...My car is at the dealer will post how much it costs as vehicle is out of manufacturers warranty an I don't believe my All State Powertrain Extended warranty will cover it.  Well see.

Did Audi sort this and if so how much did it cost please?

[NelsonP]

Audi fixed mine under warranty. It was quite a big job as they had to ensure all the water was drained out. Took a couple of weeks! I would not want to be paying for it personally, and you should not have to. It is a common fault due to poor design.

[MadMal007]

I had the same problem on my 2020 RS7, Audi want £2500 to strip interior and dry carpets with finding the leak as an extra cost. Managed to remove fasteners from the edge of the undertray and removed the front and rear bungs from both chassis rails. Water poured out but not sure how the water is getting  in there. Left the bungs out and no more problems so far.

I have an after market warranty which, of course, does not cover water ingress....

[Paddy755]

Hey Guys,

First time on this forum!

I bought an A6 C8 in August 2024, everything seemed well until I noticed a huge puddle behind the drivers seat footwell a few weeks ago.

It appears its the same/similar problem everyone is also experiencing, took it to Audi Manchester a few days ago for a check - £145 an hour! they said they needed another 8-10 hours to remove the seats and carpet to identify the leak!! Decided not to pay the £1400 minimum and took the car home. My issue is exactly the same as Mandeep. 

Will be taking it to an independant garage for a diagnosis (cheaper labour rate) 

In the meantime drafted a letter to send to Audi head office, I will paste it below in case anyone else needs to use the draft etc

Going off all the posts above i'm sure Audi are aware of the issue, whether they will honour the repair remains to be seen, but not holding my breath.

I will report back once I have had a response from head office.

 

Dear Audi Customer Services,

I hope this message finds you well. My name is   ******* *****, and I am reaching out to formally raise an issue with my Audi A6 C8, which I believe stems from a known design flaw.

I have been experiencing water pooling under the carpet in the rear footwell, specifically behind the driver’s seat. After conducting some research, I discovered that this is a common problem among Audi A6 C8 owners, and Audi has issued a Technical Service Bulletin (TSB) outlining the issue as a design fault. You can view the TSB here:

TSB - Audi A6 C8 Water Leak

Additionally, I came across this thread on the Audi Owners Club, where other owners have reported the same issue:
Discussion Thread - Audi Owners Club

This issue is one that Audi is already aware of, and it has even led to a class action lawsuit against the company, specifically related to the water leaks in the Audi A6 C8. This highlights the extent of the problem and reinforces that it is not an isolated issue, but a design flaw that has affected many owners.

Despite this being a known problem, I recently paid £152 for a diagnostic check at Manchester Audi, yet they were unable to identify the source of the leak. However, based on my online findings, the TSB issued by Audi, and the class action lawsuit, it is clear that this is not an isolated incident and is related to a design issue, rather than something I have caused or neglected.

I am aware that Audi has previously honoured this issue and, on occasion, has fixed the problem free of charge for affected customers. Given that this is a design flaw and not an error on my part, I kindly request that Audi UK address the issue in a similar manner, as a goodwill gesture.

I trust that Audi UK will stand by the quality of its vehicles and rectify this issue without further delay. I would appreciate a swift resolution and look forward to your prompt response.

Thank you for your attention to this matter.

I hope this letter helps someone who may need it. 
 

[NelsonP]

Great letter.

Fwiw, my previous car was a 2010 Audi A4 2.0 TFSI. It had the high oil usage problem that was caused by mis-specced piston rings.

There was also a TSB and class action suit on that. The usage level needed to get to 1 litre / 1000 km before Audi would look at it (!)

I wrote a v similar letter to Audi UK, sent via my local dealer, and they agreed to fix it despite the car being out of warranty. Very good of them. £6k  engine out job.

Good luck!

Edited 1 hour ago by NelsonP

[Paddy755]

Thanks Doug,

I have emailed the letter directly to Audi UK, but as you went through your local dealer and they honoured it I think i'll also send them one for good measure. 
 

Thanks