Automotive Air Conditioning Information Forum

People,

2010 Cobalt LT, original owner, for the first 6 years no problem with ac. Recently, I get periodic flooding of water from the evap, all over my passenger floor. A big puddle. So I tried to wet vac suck the drain tube from the engine bay. Worked for about 2-3 weeks. Then flooding again. So I tried first a wet vac suction followed by an air compressor blast or 2. This also worked for say, a month. Then, flooding again,. Sheesh. What is it with these Cobalts? Anyone here have any idea as what to do other than yank the dash and get inside the evap box?

The first time I got flooded the blower motor was rusted out, so I had to remove/restore the entire motor. Screwed it back on and ac worked for a bit until flooded again. So far motor is not squeaking or anything, but I am concerned.

Thanks.

If the drain tube is not the source of the back up, then the issue is in the evaporator box.

On some vehicles the bottom of the evaporator box can be removed without removing the dash.

I can't really recommend drilling that evap drain tube out and threading in a larger hose barb (one would need to make sure not to damage the evaporator coils themselves), but I'd guess someone, somewhere has done similar.

Cusser wrote:If the drain tube is not the source of the back up, then the issue is in the evaporator box.

On some vehicles the bottom of the evaporator box can be removed without removing the dash.

I can't really recommend drilling that evap drain tube out and threading in a larger hose barb (one would need to make sure not to damage the evaporator coils themselves), but I'd guess someone, somewhere has done similar.

Thanks, cusser, so what could that problem be in the evap box? A hole developed? What else?

Noquacks wrote:Thanks, cusser, so what could that problem be in the evap box? A hole developed? What else?

Likely leaves. debris, or mold clogging the evaporator drain.

If the drain tube is clear, not kinked or otherwise clogged with debris/mold, another possibility is the evaporator box was not properly installed in the car to begin with (i.e., plumb & level, so the condensate water flows towards the drain tube). Sometimes the design of the box itself, plus any mechanical slop in the mounting can result the bottom of the box being a bit off level, sloping away from the drain hole.