AC Evaporator Not Draining

Ever since I got my 97 Riviera their has been a musty interior odor that I can't get rid of, must of sprayed a whole can of Lysol into exterior vents with the A/C on hi with no results.  I just had my A/C compressor replaced and sorted out the A/C system but I have noticed that the evaporator (original) is not draining after running the A/C for a while.  I took a pen and pushed it through the drain hole on the fire wall, nothing happened.  Anyone have any advice?  Have the same issue?  Should I use compressed air?  A long screw driver? I don't want to damage the evaporator.

Thanks

Well, that sucks. A real musty, almost chemical smell coming from the vents is a good indication that the EVAP Core has a small leak. The refrigerant seeps out very slowly, and any dust that goes through the case sticks to it and gets moldy, causing the smell.

The HVAC case isn't going to drain any water unless it's really humid and hot outside. Without the heat/humidity, there isn't any moisture in the air to build up on the core and drain out of the hole.

Who replaced and recharged your Compressor? A vacuum test with the A/C machine will tell you if it's leaking. You might even have to let it sit overnight with the A/C machine attached. Record the amount of vacuum applied before leaving, and see what it is in the morning. The leak might just be that small.

Interesting. It definitely does not have a chemical smell to it. Just a stale odor, like mild dampness. My mechanic replaced the compressor (leaking), accumulator, and orifice tube. I'm sure he did a vacuum test but not overnight. It wasn't hot or humid today so that should explain the lack of water. I believe I had the same evap leak with my 94 Olds 88 but I never had the smell. Thanks. I don't think I can take another issue with this car, I love it but it can't keep costing me so much money.

I say "chemical" because I guess I just know the smell.

I'm not saying that it IS leaking, but it's certainly possible. Our HVAC/heater system doesn't use a Cabin Air Filter. It's just a giant open system. Maybe it's just a little moldy on the inside which is why you have the smell. We use stuff here at the dealer to help alleviate smells like that. It's called....

Cooling Coil Coating.
P/N 12377952

I don't know if you can buy this anywhere but the dealer. If you can, I'm sure someone on this forum will chime in and say so. If you happen to go this route, be sure to read the directions. You can't just start spraying everywhere. There are specific instructions that should be followed.

Nothing worse than a car that smells like an old basement