AC door knocking sound plus no condensation ever

My 2009 Touring never has condensation, anywhere under the car, and no where in the front floorboards. I tried cleaning the condensation tube by forcing water in and out, and the water didnt seem to go anywhere.

There is also a knocking sound, like a 4" little man inside the passenger dash trying to get out, about half a dozen times and then he stops. it comes and goes, often with the car just turned off.

AC WORKS fine! It cools and heats appropriatly. Recirc seems to be fine. I have not found a corrrelation between the AC controls and the little man knocking.

Any help would be appreciated.

No codes. No engline lights.

 

1. How long do you drive it with ac on?

Doesnt seem to matter how long AC is on.

2. When you say water forced in the drain goes no where do you mean it acts like the drain tube is blocked?

yes, like its really hard to push any water into it. I really forced some water into it, and it started coming out of some horizontal seems on to the carpet on the passenger side.

3. Have you tried the evaporator foam cleaner with press in tube? It should force foam up the condensation tube drain and will not flow back until the foam liquifies. If blocked I would expect the foam to come back immediately as foam.

yes, I tried this. Foam came back quickly.

4. Have you removed the cabin air filter and carefully inspected for animal nesting?

yes

5. When ac is running full blast what is the vent temperature?

I can check,

6. With ac running is the underhood sight glass showing bubbles?[/QUOTE]

What is this?? sight glass??

 

I've tried clearing this several times. When I try to blow air or water up the drain line it is very blocked but I removed the tube and it is empty.

Should I be able to blow air freely up into the condensation line? I tried running hot water in and out of the line with soap but I could try it longer. But I didn't want to force water in there if a door is closed and it shouldn't go up in there.