# 1998 740il rear passenger back carpet wet



## tjohnson329 (Jul 30, 2007)

I have a 1998 Bmw 740il and I am having a problem with the rear passenger side carpet. The carpet keeps getting soaking wet. I have dried it and it comes back, I have tracked it down to the A/C but it only does it when the A/C is on. I need to know what can cause this. I just believe the A/C is leaking wrong, or is clogged. If anyone has gone through this and could help me I would greatly appreciate it. thanks.


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## M.Wong (Jan 9, 2003)

Does it smell like water or coolant?

Is it only in back, no signs of dampness up front or on any of the pillars? How about the headliner? (Wet headliner = trouble, could be damaged, moldy, or hanging loose.) 

Only after A/C use, not after rain or car wash?

Clogged sunroof drains often cause wet floors. Front ones are often sealed in error when the windshield is replaced. There are four, and one of the back ones could be the problem.

Loose or improperly placed plastic vapor barriers in the doors can cause water to drip into the car. Did you have any work done in the doors recently?


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## Sean McClellan (Feb 11, 2007)

Yeah, as M. Wong said, check your sunroof, it could be clogged.


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## tjohnson329 (Jul 30, 2007)

The leak is water and is only in the back passenger side of the car with no signs of dampness up front at all. When I check the leak it is more we towards the A/C vent under the seat and is less wet as it goes back towards the back seat. I at first dried it all and it then I realized it was coming back when the A/C was on. I had no work done on the doors at all, and this problem came to my attention about a couple months ago. I had nothing done to the car and nothing changed.


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## M.Wong (Jan 9, 2003)

If you mean those vents under the seat (and not the center console) I would want to know if there is anything in front of the vents, closer to the ankles of the front seat passenger, or if anything is coming from the transmission hump area. Generally, A/C issues will leak from forward of the center console, under the dash... :dunno:

Next, I would pop off the B-pillar trim and look for signs of old moisture, and also check the door seals and the bottoms of the doors. Mud and other crap can block drain pathways.


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## tjohnson329 (Jul 30, 2007)

nothing in the door jams or in the front seat areas at all they are all dry, as for the center council that seems dry to, but will double check that. I am starting to wonder if it is possible that the water the A/C is generating is not leaking out like it is suppsoe to. Just today I turned on the A/C and I put my clear plastic backpack i use for work on the rear passenger side of the floor. after realizing I quickly move it but when i pick it up it is soaked with water on the outside. I know condinsation will happen but this was drippin water as if the vent is somehow spitting water out of it. Could it be that the A/C isnt draining right?


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## M.Wong (Jan 9, 2003)

Take a look at this possibility:
AC drain tubes

Related... any chance you get a coffee pot gurgle sound from the center dash area? 
AC drain tube TIS

If you smell coolant, it could be bad heater core o-rings.
:yikes: DIY repair:









(Photo from D.Soine)


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## tjohnson329 (Jul 30, 2007)

I due get a that sound from time to time coming from the center dash.


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