So, I've been using a '94 Grand Am as my daily driver since '03 (and bought my Monte Carlo in '08, keeping the Grand Am so I can keep the Monte out of some of the snow). The Grand Am now sits at about 207,000 miles (to many people I know, they find that amazing).

Anycase, she's been holding up better then the other ones of her age as far as visible rusting.... Last week with all the rain we've been getting I noticed the foot wells on the floor were soaked (no, it's not anti-freeze, the heat cores on these when the blow send cooland through a drain in the firewall).

I thought perhaps something wrong under the cowl. Tore it apart Saturday, cleaned up what little was there, replaced weather stripping and "thought" I found the issue. Rained the following morning and I got more water in the foot wells.

Yesterday, took the passenger side kick panel out, pulled the carpet back and played the game of drizzling water over the windshield (and other parts) to see what promotes the water entering the cab. Further investigation revealed under some padding with a rubber shielf over it is rust and a small hole!!

Given age, mileage, and the fact that it's hard to say when the Grand Am will finally develope a problem that will send it to the salvage yard, I peeled as much rust as I could off, and used half a tube of chaulking to hopefully seal the hole and rusty surface. To prevent the chaulking from sticking to other stuff, I used part of a plastic shopping bag to shield it.

I know it's not a "true" repair, but I hope it will allow the interior to remain dry and perhaps get a little more life from her.....

 

I've been battling moisture issues for a while myself. These things suck!!! I feel your pain haha

 

I saw the info you got from the Grand Prix crew (about the new water diverter for the W-bodies). I was so inspired, I picked up four (one for my Monte, the Impala, my friend's Grand Prix and my dad's Grand Prix). They were cheap I gave them as "gifts" of preventative maintenance.

Now I just need to install them

Has that seemed to solve your problem in your Monte??

 

Any repair is better than no repair. We must do what we have to. That will probably hold up for a while.

 

Actually after I did that, I found out it's the windshield that was leaking on me. Fixed that up, now the driver's side is giving me some water issues. I need to track those down with trickling water all over now.

 

I've done that with my Torino... no problems out of my Monte yet. How many miles are on that Grand Am. I guess the great white north is harder on cars than here in the south too. It's never fun to trace those things down... and I can imagine it's hard to accept that your car is getting older and in more poor condition too.

 

The Grand Am is a ;94 with 207,000 on it. It's held up better then many others of it's year. One fendor got banged in after a control arm broken (the tire mashed into the fendor at that point).

I know there are some rust spots coming around, I just never thought a hole would rust through the firewall! Surprise on me.... Like I said, I am hoping this chaulking idea helps keep the interior dry again....

 

Is there a cowl vent up there to suck in air? If so, that's the culprit... that's what rusted the floor pans of all your old cars: they had cowl vents to suck air in instead of A/C. Dirt, leaves, and everything else got in tehre... trapped moisture... water had to make it's own whole out.

 

No such luck on this car.... I tore the cowl apart and thought I might find 16-17 years of debris under the cover, nope, near spotless! Some worn out weather stripping, I replaced that. The problem is how it drains water (by design). It rans through the cowl and over the back of the strut tower, down the inside of the tower tight to the firewall. I assume at a welded seam with aging seam sealer..... And where the travel appears to stop seems to line up with my rust hole....