steve veale

I have a 1996 Vett which has developed a rain water leak [when its sitting]. The floor on the passenger side gets wet whenever it rains.
I've not seen any drips from the windshield, or roof, but the top of the carpet gets wet.

I checked the drain tube on the passenger side cowl, [which is where it seems to be coming in], but it was fine, the water drained right out.

Has anyone else experianced any similar problems?

steve veale

I bought the c4 last fall. It leaked once on the drivers side floor. About a month ago, it started leaking on the passenger side floor. Its not coming in from the roof, door, or windshield as far as I can tell. The rug is wet where it angles up from the floor [towards the dashboard]. The 1st thing I checked was the the drain tubes from the cowling. I found one on each side [drivers side is behing the battery, passenger side is under the heater box] They both drain water when poured down them. I'm stumped!

rob-cyn

Mine leaks in via the doors during heavy rains. I figured mine out the the hose and a hard spray, it might help if you had someone you could sit in the car while you soak it or drive it through a touch free car wash.

bac22

I have a similar problem and it seems to be coming in through the hood vents near the wipers but not sure where or what would cause it.

jeffp1167

check the firewall drains, when they plug up a lot of water can accumulate and possibly enter the hvac system

steve veale

I found and checked two firewall drain tubes. One is behind the battery, the other behind the heater box. Someone suggested that there is a 3rd one, but I can't find it.
Any Ideas where it could be?
thanks,
Steve

jeffp1167

the 3rd will come from somewhere in the dash area and exit where the door wiring passes through the ""A" pillar on the passenger side.

there should be another right by the wiper motor as well. so maybe there are four.

bac22

Guess I need to do this too. Are the ones you found in the engine side of the firewall?

steve veale

Will check these areas tomorrow.
Can you tell me where the "a pillar" is?
thanks

steve veale

yes
drivers side is behind the battery
pass. side is below heater box [they call this one a duck billed tube]

engle1147

here is a shot of the passenger side one (red arrow points at it)

jeffp1167

I never saw this one on my 1990, so that means there are 4 of them.

engle1147

They are easy to miss because of their size. They are bigger than you'd think they'd be.



Here are 2 tips that I use to avoid future problems. Install filters over the fresh air intakes and drill some "drain" holes near the ends of the hood seal.

steve veale

Thanks for the pics, and the advise. I'll have to find the other two drain tubes, as they must be the culprits.

bac22

I'll have to dig out my FSM and see if they show the others in there. Appreciate the pictures too.

steve veale

sounds good, thanks!

resaltair

I have a 96 that had this problem.
There are 3 drain holes(channels, that I am aware of) that should be cleaned at the source.
Remove both screens and the metal plate just below the wipers above the firewall at the cowl.
The drains take the water from the cowl area and keep it from entering the HVAC system.
With the screens and plate removed you should see these catch areas or diverters
with a flashlight.
They are located on the left and right side and one in the center as you look down into the open cowl. The center one is not dead center but slightly offset to the left or right (can't remember which).
These get plugged up with debris and not allow the water to drain properly. If you live in an area with pine or fir needles, it is especially troublesome. the grid onthe screens is to large.
Hope this helps

70ZZ3 96LT4

No interior leaks, however I put a extension on the drivers side drain tube to extend it below the battery try because when water gets on the battery try it does not drain and can rust the bolts that retain the battery try to the frame. My 96 LT4 spends more time in the garage than anywhere else but my bolts securing the battery try have had damage from the water not draining from the recessed holes in the battery tray.

Crealedc

This molded rubber gasket on the door jamb was a big concern for many years at the GM development stage. It's common for in a heavy rain for it to let water into the space much like the C3 had issues with water seeping into the birdcage