Hello TGO,
I have a 1989 firebird formula with ac (which doesn't work so I never have it on). I recently just started noticing that my passenger side foot well is always damp. I did some research online about it and found it that it could either be a leaking heater core or clogged ac line. It smells like sweaty gym socks and I read that's typically the clogged ac line whereas a sweet smell would be coolant.

Where does our ac drain lines come out? And can I just blow compressed air into the line to get it free?
Is it even the ac line since I never us the ac?

Any advice helps.
Thanks

 

I'd bet dollars to donuts it's not from the AC. If you don't use the A/C it doesn't condensate, so it doesn't need to drain.

Chances are much better that you've got a water leak that is letting in rain water. GM built these cars with rather large, gaping, holes between sheet metal panels, then they went in with seam sealer and glued everything closed. The sealer has approximately a 25-30 year lifespan. As it dries out, it cracks and pulls away, and water seeps through the joints. That screen under the wipers, all the panels under there are sealed with seam sealer. The wheel wells, floor pans, etc all are sealed.

Another possibility is leaking rubber. The rubber seals dry out and deteriorate with age. An example of this is the sealer around the windshield, or the rubber weatherstripping around the doors, windows, ttops, etc. Rubber seals around the heater core, wiring harnesses, nuts and bolts, etc can all leak with age.

First I'd suggest figuring out what is leaking. Antifreeze from a heater core will usually stink, running the heat will go the windows, and the green tint is pretty unmistakable too. You can check for a leak from outside with a garden hose and running water. Once you determine if it's antifreeze or just rain water, you can figure out where it's coming from and seal the leak.

BTW, failing seam sealer leads to rust. You don't want that. Depending how much moisture you're dealing with, it'd probably be a good idea to lift the carpet up off the floor, dry up as much as you can, and keep the carpet separated until it has a chance to dry. Otherwise, the carpet padding can soak up the moisture like a sponge and hold it to the floor until you have rust. You really don't want rust.

 

first off let me say thanks for such a quick reply!

Now I don't think its a weather stripping issue because 2 years ago I did the doors and ttop seals. I'm going to assume is the sealant that is cracking you mentioned.

If the windshield area is leaking would the firewall be getting wet as well?

This weekend I'll peel up the carpet to see if it could possibly be coming from underneath the car.

Once I find the leak would something like Flex Seal work to re-seal the area? If not, what do you recommend on using?

Thanks

 

Water will flow with gravity, so start at the wet spot, and work your way up until you identify the source. Drop the hush panel under the dash, pull the kick panel, and the door sill if necessary, and you can roll the carpet back a bit. When the floor pan transitions to the firewall there's a seam, and also you'll see the bottom edge of the firewall insulator pad. You'll want to check under that pad for water. You should be able to follow the water back to the source.

If you need to seal a car, you're really best off using a product for that purpose. Most local auto parts stores will have cheap tubes of seam sealer that can be applied with a typical caulk gun from the home improvement store. Like most things, you can fix it quick, or fix it right. The right way is probably going to take longer, and cost more, but it'll last longer and probably cause fewer issues down the road.

But first, get under there with a good light and figure out what you're dealing with, and where its coming from.

 

Alright, thanks for all your information I truly appreciate it. I'll peel back the carpet this weekend and see where it's coming from. I found this stuff called Dynatron and it's an auto seam sealer made by 3M. I think I'll give that a try and let you know what I find.

 

heater core

20 minute swap for a firebird

 

FYI

the AC condenser is in front of the radiator. It's function is to exchange heat from the pressurized refrigerant gas with the outside air allowing the gas to lose heat energy and condense into a liquid.

the AC evaporator is in the cowl at the firewall (what you're referring to). It allows the condensed refrigerant (liquid) to exchange heat energy with the cabin air and change state to a gas. This cools the cabin air as the refrigerant gains heat energy in the evaporator coil.

The evaporator removes two types of heat energy from the cabin air, latent and sensible heat energy. The sensible heat energy results in a lower temperature for the cabin air, the latent heat energy is the amount of water vapor that is condensed out of the cabin air. The cabin air, after passing through the evaporator coil has a lower temperature AND a lower humidity level.

the humidity that is removed from the cabin air becomes condensate and drains off of the evaporator coil through a drain at the bottom of the AC box. This condensate is the water that drips from under your car in that area when the AC is run. This is the condensate drain that may clog and overflow into the cabin area. If the AC is not running, no condensate is produced and the box cannot over flow into the cabin.

There is another drain in the fresh air intake (screened area at the base of the windshield) that allows rain water (or other water) to drain out of this area that can clog, leading to rust and possible intrusion into the cabin. This is also unlikely but possible.

No big if you didn't know this and I apologize if you did and simply mis-typed, but it is our job as car guys to learn these kinds of things.

 

Hey naf thanks for the reply. Yeah I was in a rush when I typed the thread up and wasn't sure whether the condenser or evaporator that had a drain.

Anyways, I did think about it being the heater core but the wet floor isn't really sweet smelling so I'm assuming it's raining water getting in. I'm going to pull back the carpet and spray water underneath the car to see if I can find the leak in the body panels like Drew said.

Is there any other symptoms to it being a leaking heater core other than the wet spot smelling like coolant?

 

foggy windshield

hopefully it's the heater core and not some rot somewhere.

 

Well I don't get foggy windshields and the carpet doesn't smell like antifreeze... So looks like it is water getting in somewhere

 

Bingo was his name-o. Just pulled up the carpet and there she was, the seam sealer is just deteriorated all to hell and that's exactly where the leak is coming from. Didn't even need to use water to find it. I'll have to clean up the old sealer and put new down. Makes me think I should do the driver side as well

 

Be sure to poke around and be thorough. There are a ton of seams with old sealer, and plenty of rubber grommets and seals around cables, wiring, etc. All of them can leak with age. You can usually test the sealer by poking at it, it should be somewhat flexible. If it's rock hard, or falls off when you poke it, it needs to be removed and replaced with fresh sealer. Don't neglect to check the sealer around the outside of the cowl. Any leaks in the sealer under the wiper screen can let water run inside the car, or inside of compartments where it shouldn't be. That can lead to leaves and trash that collect at the cowl around the wipers and under the hood, getting washed into the drains, where it can collect and you can get rust in the kick panels, rockers, floors, etc.

 

sorry to hear that. looks like it's patch panel time.