What is this and should it have water???

[dhamp]

When I drove my truck right before Thanksgiving, my son point out some liquid that dripped on the floor below the glove compartment. Of course, first thing I thought was heater core.

I was planning to drive it to work today and I had a little time to kill last night, so I started her up and kicked on the defrost just to look things over since it had been a month. When I got back in the truck, there was a few small puddles of liquid on the floor. I got a finger sample to smell it, but it didn't smell like coolant. Just water. I looked under the sash to see where it was coming from and it was leaking from the spot in this photo. There is a seam there where this piece is attached to another by those 2 screws. Could it be some kind of condensation from the heated air and color cab temp?

I gently tighted the right screw, but the left one wouldn't tighten. It just kept spinning. This morning, I drove it about 20 miles to work and nothing came out.

 

[89Suburban]

Is your A/C system operational?

 

[dhamp]

No....

 

[89Suburban]

No....

I would like to see Chengy's response to this. Was it raining those days? Wondering if there is a leak in the firewall or windshield seal. That vent tube is for the dash vents so it has to be coming in from the blower housing. Could be some stuff piled up in there possibly like leaves and pine needles and helicopters blocking the drain on the housing?

 

[dhamp]

It did rain a lot on Sat, but my truck is under the cover so condensation is about all that gets through. For the same reason, I wouldn't think there would be any build up of leaves. So you don't think it's the hot air blowing into the cold ductwork and causing a puddle at the low point in the system? (I'm assuming that it's a low point) Kinda like the same thing that causes water to drip from tail pipes?

EDIT: I forgot to mention that the couple of times it's happened, it leakes a few big drops, but then it's like it dries up. Or as if something created the water as a single glob, then it stops. So after that water is out, there's no more leaking. It's not a continual drip. Another reason I was thinking maybe some kind of condensation.

 

[89Suburban]

I highly doubt there is that much condensation forming just from warm air entering the cold duct work. That's why I asked if the A/C system was working because I can see that being a source if the of condensation if the drain was clogged. I'm gonna sit this one out and wait for some other's experiences and opinions on this, definitely got my attention getting it figured out. One thing you could try in the mean time is removing that duct that is bolted on there and next time it leaks look in that opening with a flash light and try to trace it and see where it leads to or what direction.

 

[chengny]

Even though you are not running the AC, rain water can get in the evap housing. If the drain hole is plugged, it can eventually build up a level. When it gets high enough, it can carry over into the air handling system along with the incoming air. This image shows the location - the evap housing is upside down:

 

[dhamp]

Even though you are not running the AC, rain water can get in the evap housing. If the drain hole is plugged, it can eventually build up a level. When it gets high enough, it can carry over into the air handling system along with the incoming air. This image shows the location - the evap housing is upside down:

Hmm...with it being covered up, I wouldn't think rain water would be an issue. However, I'm still going to try to find that drain hole tonight. I'm trying to flip your pic over in my head to pin point where I need to look. I'm guessing it'll be pointing down, and about centered with the glove box? Would there be a hose connected to it normally? Or is it just an opening?

UPDATE: I drove it home from work last night with the temp set about 1/4 way from the hot side because it wasn't that cold and not a single drop came out.

 

[chengny]

Kinda blew by these:

my truck is under the cover & Is your A/C system operational? No....

Tell me if I am reading this right:

Your truck is normally covered (by a tarp or something ) and the air conditioning system is non-functional - correct?

Also, are certain that the liquid that drips out is not engine coolant (leaking from the heater core)?

I got a finger sample to smell it, but it didn't smell like coolant.

In my experience a normal 50/50 mix of ethylene glycol and water (i.e. engine coolant) has no discernible odor in it's cool liquid form. You only get that distinct sweet coffee smell when coolant is in it's vapor form or a liquid at engine operating temperature.

A better way to determine if it is coolant would be to taste it. Depending on how old the ethylene glycol is the liquid will either be sweet (if the anti-freeze is over 2 years old) or extremely bitter (if the anti-freeze has been replaced within the past couple of years).

About 2 years ago (due to intense pressure from the pro-animal lobby) virtually every supplier of engine coolant began adding a substance to the ethylene glycol to make it unappealing to animals:

The bitterant, denatonium benzoate, has been used in household products and anti-nail biting formulas for decades. It is added to the antifreeze and coolant made by Prestone, Old World, Valvoline, Chevron, Shell, Recochem, Safety Kleen and Exxon Mobil.


But anyway, if the liquid on the floor isn't rain water, condensation from the evaporator or coolant leaking from the heater core...IDK - that's a tough one.