I have a 2004 chevy impala LS and I am having a very perplexing problem. Everytime it rains, I have 1-2 inchs of water on the passenger side front or the passenger side back on the floor. I can't find a leak and the seals look ok, what is going on?

Hello! I have found so far that on the forums the likelyhood of this problem is the pinchweld where the body of the car or in this case the firewall curves up to met with the windshield and the use of urethane sealer or silicone is used to seal any deterioration of the existing gasket. A good recoating or spreading of the sealer will resolve the problem as well as the one on the passenger's side where the weatherstrip sits on the pinchweld above the cabin air filter as it is a good idea to seal it together since it has a tendency to slip off over time especially when going over bumps and such. There are a few videos on Youtube.com which cover the passenger's side and yet to find one to discuss the driver's side concern. This is a likely problem on many GM vehicle, but more so on the Pontiacs as the Windshield develops leaks more so around the glass.

Here's another answer on the Driver's side question of the leak on GM vehicles: Re: water in driver's side floor area Ok, update on my water leak issue.. Found out it only does it when it rains or its washed. Pulled the driver side fender liner and windshield wiper and cowl off. ( had to fix spray nozzle on passenger side wiper anyhow, was clogged, air compressor fixed that. ) So i pulled the carpet up once again, stock a deep socket under the plastic floor board cover to keep it propped up and had my daughter watch for water as I hit different spots on the firewall.. Started low and found i had a few drips coming from the grommet that the E brake goes through the firewall. That was not my problem. As i went up with The hose the problem became worse. Somewhere its was running down the firewall and getting in through a cracked factory seam seal where the kick panel/firewall meet. If you have looked under the carpet and under the black plastic there is a ridge that runs the length of the driver side floor board and water would pool up there then soak the foam and the carpet padding, you can’t see it unless you pull back the black plastic with the foam underneath it. I couldn’t see the crack in the seam sealer, but you could damn sure see the water pouring in.. I dried it up , cleaned it real well with rubbing alcohol, slapped down some 3m seam sealer and presto leaked fixed. FYI i have invested a lot of time trying to find this damn leak.. I hope this helps someone else to save a lot of the headache.. If you have a leak start the water low until you find leakage, that way you can pinpoint where its at.. I guess if you really wanted to pull the fender off you could seal it from the outside as well, but i think the factory just seals the interior at that point. In my previous response I addressed the passenger's side as well, but here's a reference point too. http://www.justanswer.com/chevy/18tyr-2004-impala-water-leak-pass-side-dash.html Hope this helps on both sides of the vehicle leaks.

Same here I noticed it leaking at the seam

Hello! I have a 2004 Chevy Impala and I notice when it rain, water is coming in on the passenger side front floor. What can I do, to resolve this problem? Thanks in advance!