I first noticed the problem when my car started to smell funny. Then something fell on the floor in front of the passenger seat and when I picked it up, it was all wet. I had quite a puddle over there. I parked the car in the garage to get it dried out and I discovered that it was also wet under the driver's mat. My husband did some research online, and I guess there are about a million possible causes and they all have different solutions, so we are tempted to just trade it in. My husband decided to start with the sunroof. He used an air compressor to blow through the drains. I thought that had worked until today. I've been parking my car outside in the rain for about a week, and the mats have not been wet, but last night I drove the car through a car wash and this morning the inside of the windshield was covered in condensation and the carpet was wet under the front floor mats. This morning I read that sometimes the air conditioning can be the problem. I had some trouble with the air conditioning the other day. It was really hot, but the air conditioner would only blow hot air, so I turned it off and rolled down the window, but the next day, when it wasn't quite so hot, the air conditioner seemed to work just fine. Any tips or advice will be very much appreciated.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Try cleaning out the a/c evaporator drain hose. It should be on the passenger side engine firewall. Blowing compressed air or using a pipe cleaner will usually do the trick. You will generally hear water sloshing around inside the car with this condition.
The padding under the carpet is wet, so even if you find and fix source of the leak, there will still be moisture, and condensation, inside the car.
The only way to dry the padding is to remove it from the vehicle, which involves lifting the carpet itself. Shop vacs, or detailing, etc, will not remove the water from the padding, which is like a sponge, and can hold LOTS of water.
Some of the interior trip pieces will have to be removed in order to get at the padding. You'll be amazed at how wet it is under the carpet.
The sunroof drain lines are a possibility, as you said. Some people use string trimmer line instead of compressed air. I’ve been warned that you need to do this carefully, as you can have a real mess if you accidentally detach one.
The air conditioner drain line is a possibility, as mentioned above.
Another possibility is a leaking front windshield seal. I’ve seen this one mentioned occasionally on the Acura MDX message boards that I follow.
You could try taking the car to a high-pressure car wash and spraying the wand in various areas to see if you can nail down the source.