Hi all,

I own a 2017 Audi S3 (right-hand drive) and have noticed that the driver-side carpet is getting wet. The water begins accumulating in the top left corner (see attached photo) beneath the plastic footrest.

Here’s what I’ve observed so far:

• I dried out the carpet completely and left the car unused for two weeks while on holiday. During this time, the carpet remained dry, which makes me think it’s not due to rain or an external leak.
• However, since resuming use of the car, the carpet has started getting wet again, which points to something internal causing the issue.

I suspect it might be related to the air conditioning drainage pipe being blocked or malfunctioning.

• Does anyone have experience diagnosing or fixing a blocked AC drain on the Audi S3?
• If so, where exactly is the drain located in the 2017 model (RHD), and how can I check or clear it?

For additional context:

• The water feels and smells neutral (not like coolant).
• The coolant level in my car has stayed consistent.
• I’ve ruled out rainwater leaks as this issue persists regardless of weather, and the windshield has been replaced twice with no effect.
• I DO NOT have a sun-roof.

Any advice or guidance would be much appreciated. Thanks in advance!

I'd recommend you look at the scuttle panel to see if the drain holes are free from foliage. If they're blocked then water can build up and leak through the bulkhead. 

In addition, you could look, at the windscreen as failed seals/glue etc can fail. Especially if it's not the original windscreen. 

Also, is the car loosing any coolant? 

Or the heater not working properly? I ask as a failing/leaking heater matrix could be the issue. 

As Steve Q has mentioned above 👍 I replaced my heater matrix after a lack of cabin heating as mentioned and the hoses were located in the passenger side footwell instead.

16 hours ago, Steve Q said:

I'd recommend you look at the scuttle panel to see if the drain holes are free from foliage. If they're blocked then water can build up and leak through the bulkhead. 

In addition, you could look, at the windscreen as failed seals/glue etc can fail. Especially if it's not the original windscreen. 

Also, is the car loosing any coolant? 

Or the heater not working properly? I ask as a failing/leaking heater matrix could be the issue. 

I'll take a look at the scuttle panel but I'm quite confident it's not that.

As mentioned, I left the car unused for 2 weeks and it remained completely dry. It's only after using the car the carpet gets wet which is suggesting it's internal. The water doesn't smell of coolant and my coolant levels aren't going down so I think it has to be the air conditioning drainage pipe.

13 hours ago, Scallytoes said:

As Steve Q has mentioned above 👍 I replaced my heater matrix after a lack of cabin heating as mentioned and the hoses were located in the passenger side footwell instead.

The passenger side is completely dry, no issues what so ever so again it's pointing towards the AC drainage pipe for me.

Hello J ( could you please let us know your proper name). 
Looking at it logically, you cannot be confident that it isn’t the scuttle panel drain, until you inspect a them and confirm whether the problem is there or not.
Anything short of that must be an assumption.
Similarly, it is an assumption that the Air Con drain tube is at fault, until you prove it is. One possible way is to use the car without the air con on, but are you sure that the drain pipe actually run through the car as opposed to within engine compartment/ bulkhead area? 

Kind regards,

Gareth. 

 

1 hour ago, Magnet said:

Hello J ( could you please let us know your proper name). 
Looking at it logically, you cannot be confident that it isn’t the scuttle panel drain, until you inspect a them and confirm whether the problem is there or not.
Anything short of that must be an assumption.
Similarly, it is an assumption that the Air Con drain tube is at fault, until you prove it is. One possible way is to use the car without the air con on, but are you sure that the drain pipe actually run through the car as opposed to within engine compartment/ bulkhead area? 

Kind regards,

Gareth. 

 

My name is Jay. 

I'll check the scuttel panel to be sure. It's a pain using the car without the AC on as the windows steam up.

I don't know if the drain pipe runs through the car, I was hoping this forum would help confirm that. I think it's very possible though based on the points mentioned in my original post.

I am not familiar with this model, but theoretically it is possible that if the AC drain is blocked then condensate may fill the heat exchanger to the point that it overflows into the air duct and enter the cabin.

Thanks Jay,

I can understand it being a pain not using the AC in this weather, but needs must.
I’m sure it goes without saying that the floor must be dried before any test can be carried out, otherwise it’s meaningless. 
It’s now my turn to assume, but I would be surprised if any AC drain runs through the cabin area, but an assumption it has to be. 
We take it you have removed and checked the condition of the pollen filter-? 

Kind regards,

Gareth.