I recently noticed a musty smell in the car and started looking for water leaks and found the under-carpet pads in both front footwells to be soaked. When I pulled up the carpet on the passenger side, I found a hole in the floor (see attached picture), which I covered with plumber'* putty until I can effect a permanent repair. I could not find any similar situation on the driver'* side, so I am a bit perplexed as to how water entered the car on this side. After a recent rain storm, I did hear what sounded like splashing water when the A/C fan was on. If the fan housing has water in it, could it leak into the interior? Has anyone found other possible reasons for water in the driver'* footwell?

if im looking at it right its higher than normally would occur from leaking inside the car i would guess its on a seam and theres a lip on the firewall side causing you trouble

The two most common sources for water leaks in the front footwells are door panel water shields and disconnected sunroof drain tubes.

Our doors are designed to be "wet", which means water can enter the interior of the door, and is directed to drain holes in the bottom of the door. There is a plastic sheet on the inner door sheet metal that is supposed to prevent water from entering the cabin interior. That plastic sheet is attached to the sheet metal by butyl tape (black, sticky as heck) which often dries out and/or pulls off. You have to pull the trim panel off to examine the condition of the water shield, and make sure it is properly adhered to the inner door sheet metal.

Do you have a sunroof?

That looks like the same spot my 93 was leaking, but you have a much smaller rust hole than I did. Mine turned out to be the accordian tube that protects the wires between the door and the body near the emergency brake. The rubber shrinks after the years, I had to silicone all around the tube and let it dry.

Thank you for the replies.

The car does not have a sunroof. I will investigate your suggestions and report back.

I haven't found the source of the leak yet, but while searching, I did find a number of areas where corrosion could be a concern, at least on a 99 SLE. My apologies if these have been mentioned elsewhere.

1. Immediately behind each front wheel. I removed the plastic inner wheel-well shield and found approximately 5 lbs. of dirt packed into the space at the very bottom of the fender. You can also see it from the back-side by opening the front door and looking below the lower door hinge. You will probably need to remove the inner shield in order to completely clean the area. In my case, pieces of sheetmetal were missing and both sides have significant amounts of rust. Fortunately, the plastic SLE trim is doing a good job of hiding it (until the trim falls off).

2. Under the rear seat cushion, on both sides of the car, approximately 6 in. inboard of the door opening, under the carpet pad. In my case, from inside the car, the rusted areas are about the size of a quarter. Underneath, on the passenger side, the floorpan is rusting above the fuel filter, where the pan is welded to the rear subframe.

3. The bottom of the radiator cross-brace. It'* easily visible once the plastic undertray is removed.

4. The top of the RH rear wheelarch (this on has been mentioned). I found this one a few years ago when the spare wheel well in the trunk had a couple of inches of water in it.

I had a similar leak in an '86 Olds Calais. Turned out to be a clogged drain at the base of the windshield.

I suspect the driver'* side leak on my car is from the cowl/lower windshield area, since I could find no evidence of leakage along the floor next to the door and parking brake pedal. I need to find the time now to pull the carpets and padding and make an exact determination.

I removed the carpet and padding and then took the car thru a carwash to determine the location of the water leaks. On the driver'* side, I saw water leaking from under a sound deadening pad just below the red arrow in the attached photo. It then flowed down to the floor taking the path of the green arrow. Does anyone have any ideas as to the source of a leak in this area? I do not want to have to remove the dash if that can be avoided.

Check your EVAP system. Here'* a write up. There'* a vent that keeps water out of the car. https://www.gmforum.com/normal-maintainence-138/evap-clean-278997/