Just putting this out there in case anyone else has had this happen and might point me in a direction. It is wierd though.

For the past 3 weeks, whenever I take the Cutlass out for a drive, by the time we get back home I've noticed that the rug under the passenger side front mat is wet. I've been checking, and it is dry when we leave, but wet by the time we return. It seems to be water. It's clear and oderless anyway. I have not been able to find any wetness up under the dash where something could flow down under the rug. The fact that it's dry before we go out for a drive and wet by the time we get back makes me think that it is engine related. But for the life of me I can't think of how that could be happening. I know that it never happened before having the engine rebuilt this past winter.

Yes, it is a convertable. But she is kept under cover and I have not driven in the rain (or even on wet roads) this year. I'm guessing that I will have to pull the seat and the rug to find the source. But I was just hoping that this might have happened to someone else before I just start blindly searching.

 

Sounds like a leaking heater core.

 

Or a clogged AC evaporator drain if the car has AC.

 

^^^ This, the ac should run regardless if you have it on or not, causing condensation from the evaporator to drip on the rug if the hose if clogged.

 

What's the safest way to clear the evap line of a blockage?

 

Disconnect it at the connection and blast air through it (outbound). Might not be the easiest way, though.

 

The condensate drain is a rubber nipple on the bottom of the A/C evaporator box on the firewall. It is pretty much directly above the outlet of the passenger side exhaust manifold. It's usually easier to see it and access it from underneath. The rubber nipple comes off (note the spring clamp) and there are likely gross rotting leaves blocking the hole.

 

Stuff like this always amazes me. My only guess would have been the dreaded leaky heater core. I have never seen or even heard of this condensate drain. I have an A/C 70-442 and have never spotted this drain or heard of this issue.

 

Me either. Like I always say...You learn something new every day on this site.

Thanks for the input.

 

Joe,

Just out of curiousity, when I try to blow out this line should I keep the psi on my compressor below a certain amount? I was thinking in the 80-100 psi range. Do you think that is to high?

 

It's not a "line", it's a hole at the bottom of the HVAC box. Remove that spring clip, pull off the rubber nipple (repros are available when it tears), and pull out any accumulated crud. Use a non-metallic tool to do that (plastic, wood) to minimize chances of damaging the evaporator core.
Keep in mind that when you chill hot, humid air, the humidity condenses out (otherwise, A/C wouldn't work very well). Your home A/C similarly has a condensate drain.

 

It is / was very common on the Gulf Coast where I grew up. High humidity caused a lot of condensate runoff as Joe said above - some days you'd see so much water draining from under the car that it looked like the radiator blew out. The wet warm dark environment led to mold and mildew growth that eventually plugged the drain. Many people would pour a weak bleach solution into the air inlet at the base of the windshield to clean and flush the air box, or fog Lysol into the air inlet with the fan on HIGH.

 

Usually a leaking heater core will leave a smell inside your car like a cat has peed in it.

 

luckily, no smell at all.

 

Every time mine failed (way too many times over the past 40 years) it would also fog the windshield on the passengers side.

 

that's because it’s nothing more than plain water.

 

Finally got the part in last night. Put it on this morning. You were right Joe. Getting to it from underneath was much easier. One thing that was odd though. There was no old, rotted evap drain plug on there, just the locking ring and alot of what seemed like old oil on the outside. I guess it just rotted away over the years. I shined a light up in there before putting on the replacement and there was no blockage inside that I could see. I'll take her out for a drive in a little while and see if that fixed the problem.

 

Went out for a little hour long cruise.
No water under the rug!

Thanks again Joe.

 

now that you have it fixed might be a good idea to remove the seat and pull the carpet back and let it dry out for a few days.this is how floorboards rust out.my 66 the rubber strip between the drivers door and 1/4 window leaked and would get the back seat carpet wet.so i would yank the seats and console and pull the carpet out and put it in the sun to dry out then put it back in.thru the years i probably had it out a dozen times.but when i went to restore it i had totally rust free floorboards.this is pretty much unheard of on iowa cars.