I HAVE A '97 GRAND PRIX SE, GOT IT IN APRIL '04 WITH 148,000 NOW HAS 215,000 - 216,000, ONLY PROBLEM IS WATER LEAKS IN ON PASSENGER SIDE UNDER DASH - NOT HEATER CORE, WINDSHIELD, OR VENT ANY IDEAS ????????
~THUNDERKISS73

You have a sunroof? The drain hose on mine got kinked, causing water to backup, and drip on th headliner. It would then run down the headliner, into the rubber trim piece around the door opening, then down to the floor.

I took down my headliner, and saw it dripping. I tried sealing it at the sunroof but it kept dripping. I found that the drain hose, runs down inside the A-Pillar, and exits near where the door hinge is. I stuck a paperclip in there, and a bunch of water gushed out. I left the paperclip in there, and haven't had any problems since. (Been about 5 years now)

Oops... I missed the part where you said under dash... Remove the lower dash surround. You should then be able to see the blower motor. There is a cooling hose connected to it, that connects to the firewall. Some people have been reporting that water has been getting in through this, as GM redesigned the cooling hose sometime recently, as when I replaced my blower motor, the replacement was different. They told me they redesigned it, because of a problem of water leakage. If your cooling hose is short (about 4 finger widths, and is a simple L-shape, then you have the old style. If it's longer and not L-Shaped, you have the new one). They are interchangeable, but I'm not sure if you can get it without buying the motor. (If you have the old style, your motor is probably on it's last breath anyways, from all that water)

Another thing I'd look into... Open your hood, and look at the firewall on the passenger side. About arms length down, you should see a rubber elbow sticking out. This is the A/C condensation drip hose. Mine got mold growing in it, plugging it up, causing an interior stink, as well as causing the water to back up into the passenger compartment. I just stuck my finger in it, and picked off a piece of mold or something, and water gushed out. Others have reported that this elbow just fell off, causing the water to never drip out, and instead just dribble back into the car.

THANKS FOR THE INFO. !!!! I HAVE TAKEN MY CAR TO A FEW PLACES, BUT THEY TRY TO FEED ME A BUNCH OF CRAP SINCE I AM GIRL THEY THINK I AM GOING TO BELIEVE WHATEVER THEY TELL ME. ONE OF THEM EVEN TRIED TO TELL ME THE MAIN BEARING IS GOING OUT ON MY CAR, AND THAT IS THE REASON FOR THE WATER LEAKING IN !!
THANKS AGAIN !!

LOL the main bearing is going ,the guy must be smokin crack,Ithink Bryan R gave you the right imfo. Nice sig. by the way.

It's the AC drain. Here's one forum reply.
I had it on my car. Search for other threads on this site, There's a bunch.
It is the AC drain.
http://www.automotiveforums.com/vbulletin/showthread.php?t=304525&highlight=passenger+side

~THUNDERKISS73~

TRY this article http://www.oqcgp.com/forum/kb.php?mode=article&k=53

hey thuuderkiss, maybe there is one of us members that is close to you that could help you out on the stuff, also , check your heater shroud, under the dash mine moved and i had 2 inches of water after a mid summer soaker that we get, I think that it is fairly easy to realign, just kind of a pain. (I didn't do mine, cause i was already having it go to the shop, they fixed it 4 free!)

I meant thunderkiss, didn't mean to misspell it, sorry

Aren't I nice? It's below freezing outside, but I snapped a picture anyways But I did, because if I were in your position, I'd appreciate the help too

MAYBE I HAVE ALOT OF BOTH IN ME !!!

WHAT ABOUT U ?

dam it girl.....

Can't you tell????