Cabin water leak from cowl area

[TheMac]

Hi all,

I have an 87' notchback with a newly developed water leak. The car sat for about 6 months only being started to move the car around some so I wouldn't flat spot the tires. When I started to clean it up last week I found the carpets damp. After I washed it down they were soaked. I removed the plastic screen/panel underneath the wiper arms and checked the big drains and they were clear. I had my wife run some water from the hose over the cowl area while I watched from the inside of the car and water is streaming down both sides of the center tunnel under the dash. I looked for a evaporator drain tube but couldn't find one. I'm guessing the evap drain would drain off any water that runs into the AC/heater box from the fresh air intake? Any ideas on where it's coming from? Thanks Michael

[Fierofool]

The drain from the evaporator/heater core box isn't very big, intended to handle condensate from the AC core, only.  A little algae or dirt/dust buildup in it can cause it to leak into the passenger floor.  The climate control system ductwork mounts up to the underneath of the metal cowling in front of the windshield.  It may be that it's been removed at some time and the seal was damaged.  Getting it exposed isn't a terribly hard job, but it's a little time consuming. 

If you remove the instrument cluster, the vinyl radio surround and the dash, you can see everything.  There are only about 8 screws for the cluster, 4 for the shift surround, about 4 for the radio surround, 8 for the 2 front speakers and maybe another 8 for the complete dash.  It sounds as if the leak is severe enough that it should be fixed to prevent carpet rot and rusting of the floor area. 

[TheMac]

I will pull the dash. I'm switching to an automatic anyway (bad knee) and have to pull the pedal assembly.I guess I will start that project sooner than expected.  I've had the car for 4 years and never had an issue. Would the seal at the climate box to cowl just fail out of the blue? I guess anything is possible on a car this old!

[Fierofool]

I just sent you an email with a PDF file that shows the heating and ventilation system.  You can get an idea of where the leak may come from.  Part # 1 which is the main seal and Part # 8 would be suspect. 

Download and burn this to a CD.  Comes in handy when you might need to order a part that's specific to a model or year Fiero.  The part numbers can be used to cross-reference at the parts stores, and many of the parts are identified as being for a particular year/model or option equipped vehicle. 

[aerodonamic]

I did not see this posting till recently . But under the wiper arms is an plastic cowling with screens must be removed to gain acess to wiper transmission and drains ETC. The problem is it held on with 3 sheet metal screws that thru bad design go thru the cowling and yep you gussed it into the inside of the car behind the dash !!! Make sure you put sealer around the holes when reinstalling these 3 Phillips Head Screws!!!You can use silicone or a clay type puttey sealer Hope this helps fix or at least eliminate that posilibty..

[Fierofool]

I just saw a thread on PFF earlier today where a man had a heater fire due to leaves that had gotten down inside the heater ductwork.  In one of his photos, he showed the Fiero tire tool/lug wrench inserted down through the hood latch at an angle from the passenger side.  He then showed a picture from inside the driver's side just above the accelerator pedal and the lug wrench was protruding into the cabin area.  That entry point was about the center of the car above the tunnel.