A/C Leaking into cabin

pcking · 07-01-2019, 11:33 AM

So, I thought I might have the dreaded door leak or other issue, but I have found that my A/C unit is leaking water back into the cabin.

Funny part is that when it is in re-circ, I see water dripping from the trans tunnel (under the car) and no water appears to get into the cabin.

But when I have the A/C on and venting from outside, water collects quickly and leaks inside the cabin.

Getting the center console out of the car so you can actually see the bottom of the HVAC box is quite a treat. Even after pulling all that out, I cannot see a damn thing.

Also, I read somewhere that there are TWO drain ports for the A/C system, but all I can see is a small port or tube in the trans tunnel.

1. HAS ANYONE SEEN THIS BEFORE

2. ANYONE GOT A PICTURE OF WHAT THE DRAIN PORT LOOKS LIKE?

Thanks in advance!

pcking · 07-03-2019, 10:06 AM

I bought a can of that evap cleaner in the hopes that I can flush out whatever might be blocking the drain.

Also grabbed a Milwaukee Flex Inspection Scope, so I can see if I can 'look' around in there and see if I can find anything suspicious.

Not really an A/C tech - usually I rip it out of cars to make room for the cage!!!

So I am _TOTALLY_ open to any/all suggestions. ;-)

Billfitz · 07-03-2019, 10:48 AM

Identifying the drip tube in the transmission tunnel is easy, run the car with the AC on for a few minutes and water will drip out of it. The place to view it is from under the car, with the under body protection panel removed. If you don't see any dripping that would explain the water in the cabin. I don't see why vented versus recirculate would make any difference.

montr · 07-03-2019, 11:02 AM

Air in the cabin is likely drier than outside air. This is why you see the water dripping in the cabin when A/C is getting outside air if you have a restriction in the evaporator drain. You can try blowing air in the drain tube under the car to clear the restriction.

Enabled · 07-03-2019, 02:53 PM

The tube is on the right side of the transmission, right around where the transmission oil filler is. It has a flap to prevent stuff going in, it would be very unusual for it to clog up, with all the covers and things.

pcking · 07-03-2019, 03:00 PM

Thanks for your replies - I'm planning on getting back under the car tomorrow and will see if I can flush out the port. The fact that is has a flap is cool and all, but its kinda hard to see if anything is stuck in there.

When I run the A/C in MAX mode, water drips from under the car as expected.

Only when I run the AC with Re-Circ off does it leak into the car. To the earlier point, if the outside air is more humid, maybe the drain is partly clogged and therefore the higher humidity air generates more condensation and perhaps it overwhelms the drain which might be partly clogged.

CrumbyButter · 07-03-2019, 03:38 PM

The official BMW method for cleaning the AC evap and drain is from the inside, you have to remove the panel under the glove box and the cabin filter. You can then snake an AC cleaning tube up and around the bend. You will see the foam coming out the drain tube below the car. Just make sure you have something to catch the excess foam that will backup into the interior and onto your passenger side floor. Be sure to close all vents and put it in recirc mode.

Not sure this will help if its the drain tube is super badly clogged.

Enabled · 07-03-2019, 05:01 PM

Seeing the other AC thread sparked this thought...
I think your evaporator core is freezing up, at least partially, and blocking the drains. It matches with it doing it in recirc only.

pcking · 07-05-2019, 07:16 PM

Quote:

Originally Posted by Enabled

Seeing the other AC thread sparked this thought...
I think your evaporator core is freezing up, at least partially, and blocking the drains. It matches with it doing it in recirc only.

https://f30.bimmerpost.com/forums/sh...d.php?t=998638
https://f30.bimmerpost.com/forums/sh....php?t=1284006

Interesting - I'm going to investigate this further. Thanks for the pointer.

HighlandPete · 07-06-2019, 04:04 AM

Quote:

Originally Posted by pcking

Only when I run the AC with Re-Circ off does it leak into the car. To the earlier point, if the outside air is more humid, maybe the drain is partly clogged and therefore the higher humidity air generates more condensation and perhaps it overwhelms the drain which might be partly clogged.

That's where my mind is going, could fit your experience.

I'd be searching out the drain tube and make sure it's running free.

Billfitz · 07-06-2019, 07:21 AM

Quote:

Originally Posted by CrumbyButter

The official BMW method for cleaning the AC evap and drain is from the inside

True, but it's a bizarre choice. There are quite a few threads about stinky AC, and how the best fix is to inject coil cleaner up through the drain tube. It does the job very well, mine has remained stink free for over a year now. It's a PITA because you have to drop the under body shield to get at it, but it's far easier than what it takes to do it from inside the car.

pcking · 07-10-2019, 09:20 AM

Quote:

Originally Posted by Billfitz

True, but it's a bizarre choice. There are quite a few threads about stinky AC, and how the best fix is to inject coil cleaner up through the drain tube. It does the job very well, mine has remained stink free for over a year now. It's a PITA because you have to drop the under body shield to get at it, but it's far easier than what it takes to do it from inside the car.

Well for what its worth, I have all the covers off and the console in a million pieces trying to find the leak. By comparison, I sorta wish it was just a PITA... this has turned full CLUSTER!!!

IK6SPEED · 07-10-2019, 05:25 PM

Quote:

Originally Posted by pcking

Quote:

Originally Posted by Billfitz

True, but it's a bizarre choice. There are quite a few threads about stinky AC, and how the best fix is to inject coil cleaner up through the drain tube. It does the job very well, mine has remained stink free for over a year now. It's a PITA because you have to drop the under body shield to get at it, but it's far easier than what it takes to do it from inside the car.

Well for what its worth, I have all the covers off and the console in a million pieces trying to find the leak. By comparison, I sorta wish it was just a PITA... this has turned full CLUSTER!!!

Did you take your entire dashboard out?

pcking · 07-16-2019, 11:44 AM

Quote:

Originally Posted by IK6SPEED

Did you take your entire dashboard our?

That might be next. I was away last week so I still need to get back to this project. Driving around on 90 degree days with no AC sux!!!

IK6SPEED · 07-16-2019, 12:27 PM

Quote:

Originally Posted by pcking

Quote:

Originally Posted by IK6SPEED

Did you take your entire dashboard our?

That might be next. I was away last week so I still need to get back to this project. Driving around on 90 degree days with no AC sux!!!

Your post above sounds as you had already done this.

The center console is a walk in the park compared to the dashboard. Not something I'd recommend to 99.9% of the population.

IK6SPEED · 07-16-2019, 12:28 PM

Quote:

Originally Posted by pcking

Quote:

Originally Posted by IK6SPEED

Did you take your entire dashboard our?

That might be next. I was away last week so I still need to get back to this project. Driving around on 90 degree days with no AC sux!!!

Your post above sounds as you had already done this.

The center console is a walk in the park compared to the dashboard. Not something I'd recommend to 99.9% of owners.

pcking · 08-30-2019, 03:38 PM

Sorry to have left this for so long, but I had a PC failure.

I was able to fix this by using a can of evap cleaner up the drain tube opening. As it turns out, the hose/falp was basically glues shut by the dirt that has collected in there.

After prying it open (and getting lots of dirt in my eyes) and then using the cleaning kit, the issues is gone and the AC even smells nice too.

And now, I had not removed the dash, but did yank the console. While not that much of a PiA to re-install, I realize now that it did nothing to help me find/fix the leak. In the end, just a simple clogged drain tube.

07-01-2019, 11:33 AM	#1
pcking Private 88 Rep 69 Posts Drives: 2014 BMW 320i xDrive Join Date: Dec 2018 Location: West Babylon, NY iTrader: (0)	A/C Leaking into cabin So, I thought I might have the dreaded door leak or other issue, but I have found that my A/C unit is leaking water back into the cabin. Funny part is that when it is in re-circ, I see water dripping from the trans tunnel (under the car) and no water appears to get into the cabin. But when I have the A/C on and venting from outside, water collects quickly and leaks inside the cabin. Getting the center console out of the car so you can actually see the bottom of the HVAC box is quite a treat. Even after pulling all that out, I cannot see a damn thing. Also, I read somewhere that there are TWO drain ports for the A/C system, but all I can see is a small port or tube in the trans tunnel. 1. HAS ANYONE SEEN THIS BEFORE 2. ANYONE GOT A PICTURE OF WHAT THE DRAIN PORT LOOKS LIKE? Thanks in advance! __________________ Mods: Stoptech Sport Brakes, Injen Intake, BMS Catch Can, AFE Downpipe & 328i Sport Exhaust, Evolution Raceworks Chargepipes, VRSF intercooler, AFE tBody Spacer, MHI Big Turbo, BM3 Stage 2 93 Octane tune, Bilstein B8 Sport+ dampers, Dinan Perf Spring Set & Camber Plates Last edited by pcking; 07-03-2019 at 07:24 AM.. Reason: Typos
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07-03-2019, 10:06 AM	#2
pcking Private 88 Rep 69 Posts Drives: 2014 BMW 320i xDrive Join Date: Dec 2018 Location: West Babylon, NY iTrader: (0)	I bought a can of that evap cleaner in the hopes that I can flush out whatever might be blocking the drain. Also grabbed a Milwaukee Flex Inspection Scope, so I can see if I can 'look' around in there and see if I can find anything suspicious. Not really an A/C tech - usually I rip it out of cars to make room for the cage!!! So I am _TOTALLY_ open to any/all suggestions. ;-) __________________ Mods: Stoptech Sport Brakes, Injen Intake, BMS Catch Can, AFE Downpipe & 328i Sport Exhaust, Evolution Raceworks Chargepipes, VRSF intercooler, AFE tBody Spacer, MHI Big Turbo, BM3 Stage 2 93 Octane tune, Bilstein B8 Sport+ dampers, Dinan Perf Spring Set & Camber Plates
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07-03-2019, 10:48 AM	#3
Billfitz Lieutenant General 8218 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	Identifying the drip tube in the transmission tunnel is easy, run the car with the AC on for a few minutes and water will drip out of it. The place to view it is from under the car, with the under body protection panel removed. If you don't see any dripping that would explain the water in the cabin. I don't see why vented versus recirculate would make any difference.
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07-03-2019, 11:02 AM	#4
montr Captain 157 Rep 714 Posts Drives: 2010 335d, 2018 430i G-Coupe Join Date: Sep 2009 Location: Atlanta, GA iTrader: (0)	Air in the cabin is likely drier than outside air. This is why you see the water dripping in the cabin when A/C is getting outside air if you have a restriction in the evaporator drain. You can try blowing air in the drain tube under the car to clear the restriction.
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07-03-2019, 02:53 PM	#5
Enabled Lieutenant Colonel 1406 Rep 1,797 Posts Drives: 328xd Wagon, M2 Competition Join Date: Jun 2018 Location: Houston iTrader: (0)	The tube is on the right side of the transmission, right around where the transmission oil filler is. It has a flap to prevent stuff going in, it would be very unusual for it to clog up, with all the covers and things. __________________ -2014 328d Wagon, 8HP. Self-tuned, 270hp/430ft-lbs. -2019 M2 Competition MT, Alpine White. Self-tuned 560hp -2016 Mini Cooper S, MT. Many plans. Others: -E36 328is. 2000 Z3 Roady. 2003 VW Jetta TDI Manual. Estoril Z3M Coupe.
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07-03-2019, 03:00 PM	#6
pcking Private 88 Rep 69 Posts Drives: 2014 BMW 320i xDrive Join Date: Dec 2018 Location: West Babylon, NY iTrader: (0)	Thanks for your replies - I'm planning on getting back under the car tomorrow and will see if I can flush out the port. The fact that is has a flap is cool and all, but its kinda hard to see if anything is stuck in there. When I run the A/C in MAX mode, water drips from under the car as expected. Only when I run the AC with Re-Circ off does it leak into the car. To the earlier point, if the outside air is more humid, maybe the drain is partly clogged and therefore the higher humidity air generates more condensation and perhaps it overwhelms the drain which might be partly clogged. __________________ Mods: Stoptech Sport Brakes, Injen Intake, BMS Catch Can, AFE Downpipe & 328i Sport Exhaust, Evolution Raceworks Chargepipes, VRSF intercooler, AFE tBody Spacer, MHI Big Turbo, BM3 Stage 2 93 Octane tune, Bilstein B8 Sport+ dampers, Dinan Perf Spring Set & Camber Plates
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07-03-2019, 03:38 PM	#7
CrumbyButter Private First Class 25 Rep 110 Posts Drives: BMW 320i xDrive Join Date: Apr 2019 Location: New York iTrader: (0)	The official BMW method for cleaning the AC evap and drain is from the inside, you have to remove the panel under the glove box and the cabin filter. You can then snake an AC cleaning tube up and around the bend. You will see the foam coming out the drain tube below the car. Just make sure you have something to catch the excess foam that will backup into the interior and onto your passenger side floor. Be sure to close all vents and put it in recirc mode. Not sure this will help if its the drain tube is super badly clogged.
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07-03-2019, 05:01 PM	#8
Enabled Lieutenant Colonel 1406 Rep 1,797 Posts Drives: 328xd Wagon, M2 Competition Join Date: Jun 2018 Location: Houston iTrader: (0)	Seeing the other AC thread sparked this thought... I think your evaporator core is freezing up, at least partially, and blocking the drains. It matches with it doing it in recirc only. __________________ -2014 328d Wagon, 8HP. Self-tuned, 270hp/430ft-lbs. -2019 M2 Competition MT, Alpine White. Self-tuned 560hp -2016 Mini Cooper S, MT. Many plans. Others: -E36 328is. 2000 Z3 Roady. 2003 VW Jetta TDI Manual. Estoril Z3M Coupe.
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08-30-2019, 03:38 PM	#17
pcking Private 88 Rep 69 Posts Drives: 2014 BMW 320i xDrive Join Date: Dec 2018 Location: West Babylon, NY iTrader: (0)	Sorry to have left this for so long, but I had a PC failure. I was able to fix this by using a can of evap cleaner up the drain tube opening. As it turns out, the hose/falp was basically glues shut by the dirt that has collected in there. After prying it open (and getting lots of dirt in my eyes) and then using the cleaning kit, the issues is gone and the AC even smells nice too. And now, I had not removed the dash, but did yank the console. While not that much of a PiA to re-install, I realize now that it did nothing to help me find/fix the leak. In the end, just a simple clogged drain tube. __________________ Mods: Stoptech Sport Brakes, Injen Intake, BMS Catch Can, AFE Downpipe & 328i Sport Exhaust, Evolution Raceworks Chargepipes, VRSF intercooler, AFE tBody Spacer, MHI Big Turbo, BM3 Stage 2 93 Octane tune, Bilstein B8 Sport+ dampers, Dinan Perf Spring Set & Camber Plates
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