What is Causing Wet Floor in '99 Century

[HelloEvelina]

Hello everyone,

There was recently a storm here in California but it has been dry this week.

Just on Monday (December 2nd) I noticed when I got in my car (a 1999 Buick Century Custom) in the morning that the inside of the front windshield had a significant amount of condensation on it. My steering wheel cover felt a little damp, as well. I checked the floors in front and the floor on the driver side felt just a tad damp underneath my floor mats. I checked the floor in the back and behind the driver's seat is completely soaked. The bottom of the backseat is damp and so is the floor behind the passenger seat. The passenger seat floor in front seems to be the only area that's dry.

The weather stripping around all four doors seems fine. It's a wee bit cracked on the back driver side door. One canvas shopping bag has mildew on it that hangs from a hook on the back of the passenger seat headrest, other reusable shopping bags are fine. It does smell like pine trees in my car now which I assume is mold.
Since I don't have a sunroof that's not the culprit, should I have the weather shipping replaced just for the fact that it's 25 years old? But if it's not the stripping, what is causing this leakage? My carpet looks like it would need to be replaced. Of course, after the leak is corrected.

Thank you in advance for any ideas. I can provide photos if needed.

 

[century61]

Hello everyone,

There was recently a storm here in California but it has been dry this week.

Just on Monday (December 2nd) I noticed when I got in my car (a 1999 Buick Century Custom) in the morning that the inside of the front windshield had a significant amount of condensation on it. My steering wheel cover felt a little damp, as well. I checked the floors in front and the floor on the driver side felt just a tad damp underneath my floor mats. I checked the floor in the back and behind the driver's seat is completely soaked. The bottom of the backseat is damp and so is the floor behind the passenger seat. The passenger seat floor in front seems to be the only area that's dry.

The weather stripping around all four doors seems fine. It's a wee bit cracked on the back driver side door. One canvas shopping bag has mildew on it that hangs from a hook on the back of the passenger seat headrest, other reusable shopping bags are fine. It does smell like pine trees in my car now which I assume is mold.
Since I don't have a sunroof that's not the culprit, should I have the weather shipping replaced just for the fact that it's 25 years old? But if it's not the stripping, what is causing this leakage? My carpet looks like it would need to be replaced. Of course, after the leak is corrected.

Thank you in advance for any ideas. I can provide photos if needed.

I guess what I would do is take someone with you and have them sit in the back seat. Then take your car thru a car wash. See if you discover any leaks.
Since your in Cali, If the weather permits open up all the windows and let it air dry out.

 

[02LTD2.0]

Heater core is leaking.

 

[HelloEvelina]

Heater core is leaking.

If that was the case, wouldn't the front passenger floor be soaked? It is the driest. The most wet floor is behind the driver seat. It's a puddle.

 

[02LTD2.0]

The coolant flows UNDER the front carpet and forms a pool in the rear passenger foot well.
That was my experience when the heater core on my 97 Bonneville failed.

 

[chem_man]

Have you experienced a significant loss of engine coolant? Is there a sort of sweet smell in the passenger compartment as a result of the wetness?

If the answer to both questions is Yes, then you consider a leaking heater core.

I am of the opinion that you have a leak around one or both of the rear door gaskets/weatherstripping. If you can pull the gasket weatherstripping away from the body easily, then that could be where the leak is. What you need to do is to remove the gasket/weatherstripping, clean the adhesive off of the body's mating surface where the gasket "holds onto the body". Also, remove any dried adhesive that is located in the gasket's channel where the body goes into, and then take some isopropyl rubbing alcohol and clean both mating surfaces to remove any remaining grime, dirt or residues.

Now, go to virtually any auto parts store and get a 5 ounce tube of 3M Weatherstrip Adhesive, 3M part number 8001, and apply it to both the metal mating surface and the gasket/weatherstripping surface, After the adhesive dries somewhat and gets tacky, reinstall the gasket weatherstripping. This is what the stuff looks like:

https://www.oreillyauto.com/detail/c/3m/hardware---fasteners/body---trim/weatherstripping/weatherstripping-adhesive/9c1da703a8a7/3m-5-ounce-weatherstrip-adhesive/mmm0/08001?q=weatherstripping+adhesive&pos=1

Good Luck!

 

[02LTD2.0]

TYC has a lifetime warranty on their heater core.

 

[Rich B.]

All I can think of is rubber door seals, window ajar or plugged moon roof drain lines? Am pushing 80, answers are genuinely on leak lol.

 

[Mr. D]

hello Evelina, Mr.D here, I had a similar problem not somucn on driver side but from passenger side and it came from the blower motor housing, before that I had to replace the blower assembly which was rusty, that was fun, after a heavy rain front and back seat floors were soaked checking thru things I found the water coming thru fresh air intake where the cabin air filter is located, the collar in front of the filter under the windshield wiper support cover was damaged, probably when someone changed the filter, plus the car was parked in the street on a angle by the curb, passenger side tilted down, repaired the two inch collar, happy to say it fixed the leak and don't have to replace the blower again

 

[Mr. D]

hello again Evelina, forgot to mention I parked on a level section in front of my house after that, LOL